Succinoyl aminopyrazoles and related compounds

ABSTRACT

This invention is directed to a class of compounds (Formula I) including succinoyl amino pyrazoles, succinoyl amino thiadiazoles, succinoyl amino acid esters, succinoyl amino acid amides, succinoyl amino alcohols, succinoyl amino ketones, succinoyl amino hydantoins, succinoyl anilines, and succinoyl derivatives of privileged structures. The invention is also directed to a pharmaceutical formation comprising such compound in a pharmaceutically acceptable salt form or prodrug thereof. The invention is further directed to a method for inhibiting β-amyloid peptide release and/or synthesis, a method for inhibiting γ-secretase activity and a method for treating neurological disorders associated with β-amyloid peptide production. The method comprises administering to a host a pharmaceutical formulation comprising an effective amount of a compound of Formula I. The compounds of Formula I are useful in the prevention and treatment of Alzheimer&#39;s disease.

This application claims the benefit of U.S. provisional application60/378,795, filed May 7, 2002.

FIELD OF THE INVENTION

This invention relates to compounds succinoyl aminopyrazoles and relatedcompounds that inhibit β-amyloid peptide release and/or its synthesis,and, accordingly, have utility in treating Alzheimer's disease.

BACKGROUND OF THE INVENTION

Alzheimer's Disease (AD) is a degenerative brain disorder characterizedclinically by progressive loss of memory, cognition, reasoning, judgmentand emotional stability that gradually leads to profound mentaldeterioration and ultimately death. AD is a very common cause ofprogressive mental failure (dementia) in aged humans and is believed torepresent the fourth most common medical cause of death in the UnitedStates. AD has been observed in races and ethnic groups worldwide andpresents a major present and future public health problem. The diseaseis currently estimated to affect about two to three million individualsin the United States alone. AD is at present incurable. No treatmentthat effectively prevents AD or reverses its symptoms and course iscurrently known.

The brains of individuals with AD exhibit characteristic lesions termedsenile (or amyloid) plaques, amyloid angiopathy (amyloid deposits inblood vessels) and neurofibrillary tangles. Large numbers of theselesions, particularly amyloid plaques and neurofibrillary tangles, aregenerally found in several areas of the human brain important for memoryand cognitive function in patients with AD. Smaller numbers of theselesions in a more restrictive anatomical distribution are also found inthe brains of most aged humans who do not have clinical AD. Amyloidplaques and amyloid angiopathy also characterize the brains ofindividuals with Trisomy 21 (Down's Syndrome) and Hereditary CerebralHemorrhage with Amyloidosis of the Dutch Type (HCHWA-D). At present, adefinitive diagnosis of AD usually requires observing the aforementionedlesions in the brain tissue of patients who have died with the diseaseor, rarely, in small biopsied samples of brain tissue taken during aninvasive neurosurgical procedure.

The principal chemical constituent of the amyloid plaques and vascularamyloid deposits (amyloid angiopathy) characteristic of AD and the otherdisorders mentioned above is an approximately 4.2 kilodalton (kD)protein of about 39-43 amino acids designated the β-amyloid peptide(βAP) or sometimes Aβ, AβP or β/A4. β-Amyloid peptide was first purifiedand a partial amino acid sequence was provided by Glenner, et al.(Biochem. Biophys. Res. Commun., 120: 885-890)1984)). The isolationprocedure and the sequence data for the first 28 amino acids aredescribed in U.S. Pat. No. 4,666,829.

Several lines of evidence indicate that progressive cerebral depositionof Aβ plays a seminal role in the pathogenesis of AD and can precedecognitive symptoms by years or decades (Neuron, 6: 487-498 (1991)). Themost important line of evidence is the discovery that missense DNAmutations at amino acid 717 of the 770-amino acid isoform of APP can befound in affected members but not unaffected members of several familieswith a genetically determined (familial) form of AD (Goate, Nature, 349:704-706 (1990); Chartier Harlan, Nature, 353: 844-846 (1989); andMurrell, Science, 254: 97099 (1991)) and is referred to as the Swedishvariant. A double mutation changing lysine⁵⁹⁵-methionine⁵⁹⁶ toasparagine⁵⁹⁵-leucine⁵⁹⁶ (with reference to the 695 isoform) found in aSwedish family was reported in 1992 (Mullan, Nature Genet., 1:345-347(1992)). Genetic linkage analyses have demonstrated that thesemutations, as well as certain other mutations in the APP gene, are thespecific molecular cause of AD in the affected members of such families.In addition, a mutation at amino acid 693 of the 770-amino acid isoformof APP has been identified as the cause of the β-amyloid peptidedeposition disease, HCHWA-D, and a change from alanine to glycine atamino acid 692 appears to cause a phenotype that resembles AD is somepatients but HCHWA-D in others. The discovery of these and othermutations in APP in genetically based cases of AD prove that alterationof APP and subsequent deposition of its Aβ fragment can cause AD.

Aβ is derived from cleavage of APP by protease systems, collectivelytermed secretases. APP is first cleaved by β secretase to yield a βstub, which is then cleaved by γ secretase to yield a β-amyloid fragmentthat is secreted. β secretase generates the N-terminus of Aβ. γsecretase generates C-terminal fragments ending at position 38, 39, 40,42, and 43 or generating C-terminal extended precursors that aresubsequently truncated to the above polypeptides.

U.S. Pat. No. 6,153,652 discloses N-(aryl/heteroaryl/alkyacetyl) aminoacid amides, which inhibit β amyloid peptide release and/or itssynthesis, and methods for treating Alzheimer's disease with suchcompounds. U.S. Pat. Nos. 6,191,166 and 6,211,235 each discloses a classof compounds, which inhibit β amyloid peptide release and/or itssynthesis, and methods for treating Alzheimer's disease with suchcompounds. WO 00/38618 discloses succinoylaminobenzodiazepines andrelated structures and methods for inhibiting γ-secretase activity. WO00/77030 discloses statine-derived tetrapeptide inhibitors ofbeta-secretase. WO 99/66934 discloses certain cyclic amino acidcompounds that inhibit β-amyloid peptide release and/or its synthesisand methods for treating Alzheimer's disease with such compounds.

Despite the progress which has been made in understanding the underlyingmechanisms of AD and other β-amyloid peptide related diseases, thereremains a need to develop methods and compositions for treatment of thedisease. The treatment methods could be based on drugs that are capableof inhibiting β-amyloid peptide release and/or its synthesis in vivo.Methods of treatment could target the formation of Aβ through theenzymes involved in the proteolytic processing of β-amyloid precursorprotein. Compounds that inhibit y-secretase activity, either directly orindirectly, control the production of AP. Such inhibition of γ secretasecould thereby reduce production of Aβ, which, thereby, reduces orprevents the neurological disorders associated with β-amyloid peptide.

SUMMARY OF THE INVENTION

This invention is directed to the discovery of a class of compoundswhich inhibit β-amyloid peptide release and/or its synthesis. The classof compounds having the described properties are defined by formula Ibelow:

The class of compounds includes succinoyl amino pyrazoles, succinoylamino thiadiazoles, succinoyl amino acid esters, succinoyl amino acidamides, succinoyl amino alcohols, succinoyl amino ketones, succinoylamino hydantoins, succinoyl anilines, and succinoyl derivatives ofprivileged structures. The present invention is also directed to apharmaceutical formation comprising such compound in a pharmaceuticallyacceptable salt form or prodrug thereof.

The present invention is directed to a method for inhibiting β-amyloidpeptide release and/or synthesis and a method for inhibiting y-secretaseactivity. The present invention is also directed to a method fortreating neurological disorders associated with β-amyloid peptideproduction . The method comprises the steps of administering to a host apharmaceutical formulation comprising an effective amount of a compoundof Formula T. The compounds of Formula I are useful in the prevention ofAD in patients susceptible to AD and/or in the treatment of patientswith AD.

DETAILED DESCRIPTION OF THE INVENTION

This invention is directed to compounds that inhibit β-amyloid peptiderelease and/or its synthesis. The class of compounds includes succinoylamino pyrazoles, succinoyl amino thiadiazoles, succinoyl amino acidesters, succinoyl amino acid amides, succinoyl amino alcohols, succinoylamino ketones, succinoyl amino hydantoins, succinoyl anilines, andsuccinoyl derivatives of privileged structures (J. Med. Chem., 41:3103(1998), J. Comb. Chem., 1:388 (1999)). The present invention is alsodirected to a pharmaceutical formulation comprising such compound.

The class of compounds having the described properties are defined byFormula I below:

or a pharmaceutically acceptable salt or prodrug thereof,wherein X is selected from the group consisting of:

and the following privileged structures:

where the attachment point on X is —N of the N atom that has anunoccupied valency; the N atom can be either on the cyclic or acyclicpart of the structure;

-   wherein Q is —NR¹R²;-   R¹, R¹⁰ and R¹¹, at each occurrence, is independently selected from    the group consisting of:    -   H;    -   C₁-C₆ alkyl substituted with 0-3 R^(1a);    -   C₂-C₆ alkenyl substituted with 0-3 R^(1a),    -   C₂-C₆ alkynyl substituted with 0-3 R^(1a),    -   C₃-C₁₀ carbocycle substituted with 0-3 R^(1b);    -   C₆-C₁₀ aryl substituted with 0-3 R^(1b); and    -   5 to 10 membered heterocycle containing 1 to 4 heteroatoms        selected from nitrogen, oxygen, and sulphur, wherein said 5 to        10 membered heterocycle is substituted with 0-3 R^(1b);-   R^(1a), at each occurrence, is independently selected from the group    consisting of H,    -   C₁-C₆ alkyl, Cl, F, Br, I, ═O, CN, NO₂, NR¹⁷R¹⁸, CF₃;    -   C₃-C₁₀ carbocycle substituted with 0-3 R^(1b);    -   C₆-C₁₀ aryl substituted with 0-3 R^(1b); and    -   5 to 10 membered heterocycle containing 1 to 4 heteroatoms        selected from nitrogen, oxygen, and sulphur, wherein said 5 to        10 membered heterocycle is substituted with 0-3 R^(1b);-   R^(1b), at each occurrence, is independently selected from the group    consisting of H, OH, Cl, F, Br, I, CN, NO₂, NR¹⁷R¹⁸, CF₃, C₁-C₆    alkyl, C₁-C₄ alkoxy, C₁-C₆ haloalkyl, C₁-C₄ haloalkoxy, and    SO₂(C₁-C₄)alkyl;-   R² is independently selected from the group consisting of H, C₁-C₆    alkyl, C₃-C₁₀ carbocycle, C₆-C₁₀ aryl, and 5 to 10 membered    heterocycle containing 1 to 4 heteratoms selected from nitrogen,    oxygen, and sulphur;-   R³ is —(CR⁷R^(7a))_(n)—R⁴,    -   —(CR⁷R^(7a))_(n)—S—(CR⁷R^(7a))_(m)—R⁴,    -   —(CR⁷R^(7a))_(n)—O—(CR⁷R^(7a))_(m)—R⁴,    -   —(CR⁷R^(7a))_(n)—N(R^(7b))—(CR⁷R^(7a))_(m)—R⁴,    -   —(CR⁷R^(7a))_(n)—S(═O)—(CR⁷R^(7a))_(m)—R⁴,    -   —(CR⁷R^(7a))_(n)—S(═O)₂—(CR⁷R^(7a))_(m)—R⁴,    -   —(CR⁷R^(7a))_(n)—C(═O)—(CR⁷R^(7a))_(m)—R⁴,    -   —(CR⁷R^(7a))_(n)—N(R^(7b))C(═O)—(CR⁷R^(7a))_(m)—R⁴,    -   —(CR⁷R^(7a))_(n)—C(═O)N(R^(7b))—(CR⁷R^(7a))_(m)—R⁴    -   —(CR⁷R^(7a))_(n)—N(R^(7b))S(═O)₂—(CR⁷R^(7a))_(m)—R⁴, or    -   —(CR⁷R^(7a))_(n)—S(═O)₂N(R^(7b))—(CR⁷R^(7a))_(m)—R⁴;-   n is 0, 1, 2, or 3;-   m is 0, 1, 2, or 3;-   R^(3a) is H, OH, C₁-C₄ alkyl, C₁-C₄ alkoxy, C₂-C₄ alkenyl or C₂-C₄    alkenyloxy;-   R⁴ is H, OH, OR^(16a),    -   C₁-C₆ alkyl substituted with 0-3 R^(4a),    -   C₂-C₆ alkenyl substituted with 0-3 R^(4a),    -   C₂-C₆ alkynyl substituted with 0-3 R^(4a),    -   C₃-C₁₀ carbocycle substituted with 0-3 R^(4b),    -   C₆-C₁₀ aryl substituted with 0-3 R^(4b), or    -   5 to 10 membered heterocycle containing 1 to 4 heteroatoms        selected from nitrogen, oxygen, and sulphur, wherein said 5 to        10 membered heterocycle is substituted with 0-3 R^(4b);-   R^(4a), at each occurrence, is independently selected from the group    consisting of H, F, Cl, Br, I, CF₃,    -   C₃-C₁₀ carbocycle substituted with 0-3 R^(4b),    -   C₆-C₁₀ aryl substituted with 0-3 R^(4b), or    -   5 to 10 membered heterocycle containing 1 to 4 heteroatoms        selected from nitrogen, oxygen, and sulphur, wherein said 5 to        10 membered heterocycle is    -   substituted with 0-3 R^(4b);-   R^(4b), at each occurrence, is independently selected from the group    consisting of H, OH, Cl, F, Br, I, CN, NO₂, NR¹⁷R¹⁸, CF₃, acetyl,    SCH₃, S(═O)CH₃,    -   C₁-C₆ alkyl, C₁-C₄ alkoxy, C₁-C₆ haloalkyl, C₁-C₄ haloalkoxy,        and C₁-C₄ halothioalkyl-S—;-   R⁵ is H, OR¹⁶;    -   C₁-C₆ alkyl substituted with 0-3 R^(5b),    -   C₁-C₆ alkoxy substituted with 0-3 R^(5b),    -   C₂-C₆ alkenyl substituted with 0-3 R^(5b),    -   C₂-C₆ alkynyl substituted with 0-3 R^(5b),    -   C₃-C₁₀ carbocycle substituted with 0-3 R^(5c),    -   C₆-C₁₀ aryl substituted with 0-3 R^(5c), or    -   5 to 10 membered heterocycle containing 1 to 4 heteroatoms        selected from the group consisting of nitrogen, oxygen, and        sulphur, wherein said 5 to 10 membered heterocycle is        substituted with 0-3 R^(5c);-   R^(5a) is H, OH, C₁-C₄ alkyl, C₁-C₄ alkoxy, C₂-C₄ alkenyl, or C₂-C₄    alkenyloxy;-   R^(5b), at each occurrence, is independently selected from the group    consisting of:    -   H, C₁-C₆ alkyl, CF₃, OR¹⁶, Cl, F, Br, I, ═O, CN, NO₂, NR¹⁷R¹⁸;    -   C₃-C₁₀ carbocycle substituted with 0-3 R^(5c),    -   C₆-C₁₀ aryl substituted with 0-3 R^(5c), or    -   5 to 10 membered heterocycle containing 1 to 4 heteroatoms        selected from nitrogen, oxygen, and sulphur, wherein said 5 to        10 membered heterocycle is substituted with 0-3 R^(5c);-   R^(5c), at each occurrence, is independently selected from the group    consisting of H, OH, Cl, F, Br, I, CN, NO₂, NR¹⁷R¹⁸, CF₃, acetyl,    SCH₃, S(═O)CH₃, S(═O)₂CH₃,    -   C₁-C₆ alkyl, C₁-C₄ alkoxy, C₁-C₄ haloalkyl,    -   C₁-C₄ haloalkoxy, and C₁-C₄ halothioalkyl-S—;-   R⁷, at each occurrence, is independently selected from the group    consisting of H, OH, Cl, F, Br, I, CN, NO₂, CF₃, phenyl and C₁-C₄    alkyl;-   R^(7a), at each occurrence, is independently selected from the group    consisting of H, OH, Cl, F, Br, I, CN, NO₂, CF₃, and C₁-C₄ alkyl;-   R^(7b) is independently selected from the group consisting of H and    C₁-C₄ alkyl (such as CH₃);-   R¹² is H, methyl, ethyl, propyl, or butyl;-   R¹³, at each occurrence, is independently C₁-C₆ alkyl, alkeny, or    alkynyl optionally substituted with C₆-C₁₀ aryl substituted with 0-3    R^(5c);-   R¹⁴, at each occurrence, is independently selected from H, phenyl,    benzyl, C₁-C₆ alkyl, and C₂-C₆ alkoxyalkyl;-   R¹⁵, at each occurrence, is independently selected from H, C₁-C₆    alkyl, phenyl, benzyl, phenethyl, (C₁-C₆ alkyl)-C(═O)—, (C₁-C₆    alkyl)-O—C(═O)— and (C₁-C₆ alkyl)-S(═O)₂—;-   R¹⁶ is H, phenyl, benzyl, C₁-C₆ alkyl, C₂-C₆ alkoxyalkyl, or C₃-C₆    cycloalkyl;-   R^(16a) is H, phenyl, benzyl, or C₁-C₄ alkyl;-   R¹⁷, at each occurrence, is independently selected from the group    consisting of H,    -   C₁-C₆ alkyl, benzyl, phenethyl, (C₁-C₆ alkyl)-C(═O)—, and (C₁-C₆        alkyl)-S(═O)₂—; and-   R¹⁸, at each occurrence, is independently selected from the group    consisting of H, OH, and C₁-C₆ alkyl, benzyl, phenethyl, (C₁-C₆    alkyl)-C(═O)—, and (C₁-C₆ alkyl)-S(═O)₂—.

In one embodiment of the invention, the privileged structure is apiperidine or piperazine of Formula II:

-   wherein Y═C or N;-   R²⁰ is H, C₁₋₄ alkyl, —OH, CO₂R^(7b), —C≡N, or CONR²²R²³;-   R²² and R²³ are independently H, C₁₋₄ alkyl, phenyl, or together    form 5-7 member heterocycle, (CH₂)₀₋₂ NC(O)CH₃;-   R²¹ is aryl, substituted aryl, alkylaryl, or heteroaryl; or-   R²¹ and R²² together form a spirofused heterocycle of 5-7 atoms,    where the spirofused heterocycle is optionally fused with an aryl.

In another embodiment of the invention, the privileged structure is afluorene of formula III:

In a preferred embodiment:

-   R¹═R²═H.

In another preferred embodiment, the total number of carbon atoms in R³,R^(3a), R⁵, and R^(5a) are equal to seven or more.

In another preferred embodiment:

-   R³ is —(CR⁷R^(7a))n-R⁴,    -   —(CR⁷R^(7a))n-S—(CR⁷R^(7a))_(m)—R⁴,    -   —(CR⁷R^(7a))n-O—(CR⁷R^(7a))_(m)—R⁴, or    -   —(CR⁷R^(7a))n-N(R^(7b))—(CR⁷R^(7a))m-R⁴;-   n is 0, 1, or 2;-   m is 0, 1, or 2;-   R^(3a) is H, OH, methyl, ethyl, propyl, butyl, methoxy, ethoxy,    propoxy, butoxy, allyl, or 3-buten-1-yl;-   R⁴ is H, OH, OR^(16a),    -   C₁-C₆ alkyl substituted with 0-3 R^(4a),    -   C₂-C₆ alkenyl substituted with 0-3 R^(4a),    -   C₂-C₆ alkynyl substituted with 0-3 R^(4a),    -   C₃-C₁₀ carbocycle substituted with 0-3 R^(4b),    -   C₆-C₁₀ aryl substituted with 0-3 R^(4b), or    -   5 to 10 membered heterocycle containing 1 to 4 heteroatoms        selected from the group consisting of nitrogen, oxygen, and        sulphur, wherein said 5 to 10 membered heterocycle is        substituted with 0-3 R^(4b);-   R^(4a), at each occurrence, is independently selected from the group    consisting of H, F, Cl, Br, I, CF₃,    -   C₃-C₁₀ carbocycle substituted with 0-3 R^(4b),    -   C₆-C₁₀ aryl substituted with 0-3 R^(4b), or    -   5 to 10 membered heterocycle containing 1 to 4 heteroatoms        selected from nitrogen, oxygen, and sulphur, wherein said 5 to        10 membered heterocycle is substituted with 0-3 R^(4b);-   R^(4b), at each occurrence, is independently selected from the group    consisting of H, OH, Cl, F, Br, I, CN, NO₂, NR¹⁷R¹⁸, CF₃, acetyl,    SCH₃, S(═O)CH₃, S(═O)₂CH₃, C₁-C₆ alkyl, C₁-C₄ alkoxy, C₁-C₄    haloalkyl, and C₁-C₄ haloalkoxy;-   R⁵ is H, OR¹⁶;    -   C₁-C₆ alkyl substituted with 0-3 R^(5b),    -   C₁-C₆ alkoxy substituted with 0-3 R^(5b),    -   C₂-C₆ alkenyl substituted with 0-3 R^(5b),    -   C₂-C₆ alkynyl substituted with 0-3 R^(5b),    -   C₃-C₁₀ carbocycle substituted with 0-3 R^(5c),    -   C₆-C₁₀ aryl substituted with 0-3 R^(5c),    -   5 to 10 membered heterocycle containing 1 to 4 heteroatoms        selected from nitrogen, oxygen, and sulphur, wherein said 5 to        10 membered heterocycle is substituted with 0-3 R^(5c);-   R^(5a) is H or C₁-C₄ alkyl;-   R^(5b), at each occurrence, is independently selected from the group    consisting of:    -   H, C₁-C₆ alkyl, CF₃, OR¹⁶, Cl, F, Br, I, ═O, CN, NO₂, NR¹⁷R¹⁸;    -   C₃-C₁₀ carbocycle substituted with 0-3 R^(5c),    -   C₆-C₁₀ aryl substituted with 0-3 R^(5c), or    -   5 to 10 membered heterocycle containing 1 to 4 heteroatoms        selected from nitrogen, oxygen, and sulphur, wherein said 5 to        10 membered heterocycle is substituted with 0-3 R^(5c);-   R^(5c), at each occurrence, is independently selected from the group    consisting of H, OH, Cl, F, Br, I, CN, NO₂, NR¹⁷R¹⁸, CF₃, acetyl,    SCH₃, S(═O)CH₃, S(═O)₂CH₃,    -   C₁-C₆ alkyl, C₁-C₄ alkoxy, C₁-C₄ haloalkyl,    -   C₁-C₄ haloalkoxy, and C₁-C₄ halothioalkyl-S—;-   R⁷, at each occurrence, is independently selected from the group    consisting of H, OH, Cl, F, Br, I, CN, NO₂, CF₃, phenyl and C₁-C₄    alkyl;-   R^(7a), at each occurrence, is independently selected from the group    consisting of H, OH, Cl, F, Br, I, CN, NO₂, CF₃, phenyl and C₁-C₄    alkyl;-   R^(7b) is independently selected from the group consisting of H,    methyl, ethyl, propyl, and butyl;-   R¹⁴ is independently selected from the group consisting of H,    phenyl, benzyl, methyl, ethyl, propyl, and butyl;-   R¹⁵ is independently selected from the group consisting of H,    methyl, ethyl, propyl, and butyl;-   R¹⁶ is H, phenyl, benzyl, C₁-C₆ alkyl, C₂-C₆ alkoxyalkyl;-   R^(16a) is H, phenyl, benzyl, methyl, ethyl, propyl, or butyl;-   R¹⁷, at each occurrence, is independently selected from the group    consisting of H,    -   C₁-C₆ alkyl, benzyl, phenethyl, (C₁-C₆ alkyl)-C(═O)—, and (C₁-C₆        alkyl)-S(═O)₂—;-   R¹⁸, at each occurrence, is independently selected from the group    consisting of H, OH, C₁-C₆ alkyl, benzyl, phenethyl, (C₁-C₆    alkyl)-C(═O)—, and (C₁-C₆ alkyl)-S(═O)₂—.

In a further preferred embodiment:

-   R³ is —(CHR⁷)_(n)—R⁴,-   N is 0 or 1;-   R^(3a) is H, OH, methyl, ethyl, propyl, butyl, methoxy, ethoxy,    propoxy, butoxy, allyl, or 3-buten-1-yl;-   R⁴ is H, OH, OR^(16a),    -   C₁-C₄ alkyl substituted with 0-2 R^(4a),    -   C₂-C₄ alkenyl substituted with 0-2 R^(4a),    -   C₂-C₄ alkynyl substituted with 0-1 R^(4a),    -   C₃-C₆ carbocycle substituted with 0-3 R^(4b),    -   C₆-C₁₀ aryl substituted with 0-3 R^(4b), or    -   5 to 6 membered heterocycle containing 1 to 4 heteroatoms        selected from nitrogen, oxygen, and sulphur, wherein said 5 to 6        membered heterocycle is substituted with 0-3 R^(4b);-   R^(4a), at each occurrence, is independently selected from the group    consisting of H, F, Cl, Br, I, CF₃,    -   C₃-C₆ carbocycle substituted with 0-3 R^(4b),    -   phenyl substituted with 0-3 R^(4b), or    -   5 to 6 membered heterocycle containing 1 to 4 heteroatoms        selected from nitrogen, oxygen, and sulphur, wherein said 5 to 6        membered heterocycle is substituted with 0-3 R^(4b);-   R^(4b), at each occurrence, is independently selected from the group    consisting of H, OH, Cl, F, Br, I, CN, NO₂, NR¹⁷R¹⁸, CF₃, acetyl,    SCH₃, S(═O)CH₃, S(═O)₂CH₃, C₁-C₄ alkyl, C₁-C₃ alkoxy, C₁-C₂    haloalkyl, and C₁-C₂ haloalkoxy;-   R⁵is H, OR¹⁶;    -   C₁-C₄ alkyl substituted with 0-3 R^(5b),    -   C₂-C₄ alkenyl substituted with 0-3 R^(5b),    -   C₂-C₄ alkynyl substituted with 0-3 R^(5b),-   R^(5a) is H, methyl, ethyl, propyl, or butyl;-   R^(5b), at each occurrence, is independently selected from the group    consisting of:    -   H, methyl, ethyl, propyl, butyl, CF₃, OR¹⁶, Cl, F, Br, I, ═O;    -   C₃-C₆ carbocycle substituted with 0-3 R^(5c),    -   phenyl substituted with 0-3 R^(5c), or    -   5 to 6 membered heterocycle containing 1 to 4 heteroatoms        selected from nitrogen, oxygen, and sulphur, wherein said 5 to 6        membered heterocycle is substituted with 0-3 R^(5c);-   R^(5c), at each occurrence, is independently selected from the group    consisting of H, OH, Cl, F, Br, I, CN, NO₂, NR¹⁷R¹⁸, CF₃, acetyl,    SCH₃, S(═O)CH₃, S(═O)₂CH₃, C₁-C₄ alkyl, C₁-C₃ alkoxy, C₁-C₂    haloalkyl, C₁-C₄ haloalkoxy,;-   R⁷, at each occurrence, is independently selected from the group    consisting of H, F, CF₃, methyl, and ethyl;-   R¹⁶ is H, phenyl, benzyl, C₁-C₄ alkyl, or C₂-C₄ alkoxyalkyl;-   R¹⁷, at each occurrence, is independently selected from the group    consisting of H,    -   C₁-C₄ alkyl, benzyl, phenethyl, (C₁-C₄ alkyl)-C(═O)—, and (C₁-C₆        alkyl)-S(═O)₂—;-   R¹⁸, at each occurrence, is independently selected from the group    consisting of H, OH, C₁-C₄ alkyl, benzyl, phenethyl, (C₁-C₄    alkyl)-C(═O)—, and (C₁-C₄ alkyl)-S(═O)₂—.

In yet another preferred embodiment:

-   R¹═R²═H,-   R³ is R⁴,-   R⁴ is C₁-C₄ alkyl substituted with 0-1 R^(4a),    -   C₂-C₄ alkenyl substituted with 0-1 R^(4a), or    -   C₂-C₄ alkynyl substituted with 0-1 R^(4a),-   R^(4a), at each occurrence, is independently selected from the group    consisting of H, F, CF₃,    -   C₃-C₆ carbocycle substituted with 0-3 R^(4b),    -   phenyl substituted with 0-3 R^(4b), or    -   5 to 6 membered heterocycle containing 1 to 4 heteroatoms        selected from nitrogen, oxygen, and sulphur, wherein said 5 to 6        membered heterocycle is substituted with 0-3 R^(4b); wherein 5        to 6 membered heterocycle is selected from pyridinyl,        pyrimidinyl, triazinyl, furanyl, thienyl, thiazolyl, pyrrolyl,        piperazinyl, piperidinyl, pyrazolyl, imidazolyl, oxazolyl,        isoxazolyl, and tetrazolyl;-   R^(4b), at each occurrence, is independently selected from the group    consisting of H, OH, Cl, F, NR¹⁷R¹⁸, CF₃, acetyl, SCH₃, S(═O)CH₃,    S(═O)₂CH₃, methyl, ethyl, propyl, butyl, methoxy, ethoxy, propoxy,    C₁-C₂ halolkyl, and C₁-C₂ haloalkoxy;-   R⁵ is C₁-C₄ alkyl substituted with 0-1 R^(5b),    -   C₂-C₄ alkenyl substituted with 0-1 R^(5b),    -   C₂-C₄ alkynyl substituted with 0-1 R^(5b),-   R^(5b), at each occurrence, is independently selected from the group    consisting of:    -   H, methyl, ethyl, propyl, butyl, CF₃, OR¹⁶, ═O;    -   C₃-C₆ carbocycle substituted with 0-2 R^(5c),    -   phenyl substituted with 0-3 R^(5c), or    -   5 to 6 membered heterocycle containing 1 to 4 heteroatoms        selected from nitrogen, oxygen, and sulphur, wherein said 5 to 6        membered heterocycle is substituted with 0-3 R^(5c); wherein        said 5 to 6 membered heterocycle is selected from pyridinyl,        pyrimidinyl, triazinyl, furanyl, thienyl, thiazolyl, pyrrolyl,        piperazinyl, piperidinyl, pyrazolyl, imidazolyl, oxazolyl,        isoxazolyl, and tetrazolyl;-   R^(5c), at each occurrence, is independently selected from the group    consisting of H, OH, Cl, F, NR¹⁷R¹⁸, CF₃, acetyl, SCH₃, S(═O)CH₃,    S(═O)₂CH₃, methyl, ethyl, propyl, butyl, methoxy, ethoxy, propoxy,    C₁-C₂ haloalkyl, and C₁-C₂ haloalkoxy;-   R¹⁶ is H, phenyl, benzyl, methyl, ethyl, propyl, or butyl;-   R¹⁷, at each occurrence, is independently selected from the group    consisting of H, methyl, ethyl, propyl, and butyl;-   R¹⁸, at each occurrence, is independently selected from the group    consisting of H, OH, methyl, ethyl, propyl, and butyl, benzyl,    phenethyl, methyl-C(═O)—, ethyl-C(═O)—, methyl-S(═O)₂—, and    ethyl-S(═O)₂—;

In another further preferred embodiment:

-   R³is —CH₃, —CH₂CH₃, —CH₂CH₂CH₃, —CH₂CH₂CH₂CH₃, —CH₂(CH₃)₂,    —CH(CH₃)CH₂CH₃, —CH₂CH(CH₃)₂, —CH₂C(CH₃)₃, —CF₃, —CH₂CF₃,    —CH₂CH₂CF₃, —CH₂CH₂CF₃, —CH═CH₂, —CH₂CH═CH₂, —CH₂C(CH₃)═CH₂,    —CH₂CH═C(CH₃)₂, CH₂CH₂CH═CH₂, —CH₂CH₂CH═CH₂, —CH₂CH₂C(CH₃)═CH₂,    —CH₂CH₂CH═C(CH₃)₂, cis-CH₂CH═CH(CH₃), cis-CH₂CH₂CH═CH(CH₃),    trans-CH₂CH═CH(CH₃), trans-CH₂CH₂CH═CH(CH₃); —C═CH, —CH₂C═C(CH₃),    cyclopropyl-CH₂—, cyclobutyl-CH₂—, cyclopentyl-CH₂—,    cyclohexyl-CH₂—, cycloproyl-CH₂CH₂—, cyclobutyl-CH₂CH₂—,    cyclopentyl-CH₂CH₂—, cyclohexyl-CH₂CH₂—, phenyl-CH₂—,    (2-F-phenyl)CH₂—, (3-F-phenyl)CH₂—, (4-F-phenyl)CH₂—,    (2-Cl-phenyl)CH₂—, (3-Cl-phenyl)CH₂—, (4-Cl-phenyl)CH₂—,    (2,3-diF-phenyl)CH₂—, (2,4-diF-phenyl)CH₂—, (2,5-diF-phenyl)CH₂—,    (2,6-diF-phenyl)CH₂—, (3,4-diF-phenyl)CH₂—, (3,5-diF-phenyl)CH₂—,    (2,3-diCl-phenyl)CH₂—, (2,4-diCl -phenyl)CH₂—,    (2,5-diCl-phenyl)CH₂—, (2,6-diCl-phenyl)CH₂—, (3,4-diCl-phenyl)CH₂—,    (3,5-diCl-phenyl)CH₂—, (3-F-4—Cl-phenyl)CH₂—, (3-F-5-Cl-phenyl)CH₂—,    (3-Cl-4-F-phenyl)CH₂—, phenyl-CH₂CH₂, (2-F-phenyl)CH₂CH₂—,    (3-F-phenyl)CH₂CH₂—, (4-F-phenyl)CH₂CH₂—, (2-Cl-phenyl)CH₂CH₂—,    (3-Cl-phenyl)CH₂CH₂—, (4-Cl-phenyl)CH₂CH₂—, (2,3-diF-phenyl)CH₂CH₂—,    (2,4-diF-phenyl)CH₂CH₂—, (2,5-diF-phenyl)CH₂CH₂—,    (2,6-diF-phenyl)CH₂CH₂—, (3,4-diF-phenyl)CH₂CH₂—,    (3,5-diF-phenyl)CH₂CH₂—, (2,3-diCl-phenyl)CH₂CH₂—,    (2,4-diCl-phenyl)CH₂CH₂—, (2,5-diCl-phenyl)CH₂CH₂—,    (2,6-diCl-phenyl)CH₂CH₂—, (3,4-diCl-phenyl)CH₂CH₂—,    (3,5-diCl-phenyl)CH₂CH₂—, (3-F-4-Cl-phenyl)CH₂CH₂—, or    (3-F-5-C-phenyl)CH₂CH₂—;-   R⁵ is —CH₃, —CH₂CH₃, —CH₂CH₂CH₃, —CH(CH₃)₂, —CH₂CH₂CH₂CH₃,    —CH(CH₃)CH₂CH₃, —CH₂CH(CH₃)₂, —CH₂C(CH₃)₃, —CH₂CH₂CH₂CH₂CH₃,    —CH(CH₃)CH₂CH₂CH₃, —CH₂CH(CH₃)CH₂CH₃, —CH₂CH₂CH(CH₃)₂,    —CH(—CH₂CH₃)₂, —CF₃, —CH₂CF₃, —CH₂CH₂CF₃, —CH₂CH₂CH₂CF₃,    —CH₂CH₂CH₂CH₂CF₃, —CH═CH₂, —CH═CH₂, —CH₂CH═CH₂, —CH—CHCH₃,    cis-CH₂CH═CH(CH₃), trans-CH₂CH═CH(CH₃), trans-CH₂CH═CH(C₆H₅),    —CH₂CH═C(CH₃)₂, cis-CH₂CH═CHCH₂CH₃, trans-CH₂CH═CHCH₂CH₃,    cis-CH₂CH₂CH═CH(CH₃), trans-CH₂CH₂CH═CH(CH₃),    trans-CH₂CH═CHCH₂(C₆H₅), —C═CH, —CH₂C═CH, —CH₂C═C(C₆H₅),    —CH₂CH₂C═CH, —CH₂CH₂C═C(CH₃), —CH₂CH₂C═C(C₆H₅), —CH₂CH₂CH₂C═CH,    —CH₂CH₂CH₂C═C(CH₃), —CH₂CH₂CH₂C═C(C₆H₅), cyclopropyl-CH₂—,    cyclobutyl-CH₂—, cyclopentyl-CH₂—, cyclohexyl-CH₂—,    (1-CH₃-cyclopropyl)CH₂—, (-3-CH₃-cyclobutyl)CH₂—,    cycloproyl-CH₂CH₂—, cyclobutyl-CH₂CH₂—, cyclopentyl-CH₂CH₂—,    cyclohexyl-CH₂CH₂—, (2—CH₃-cyclopropyl)CH₂CH₂—,    (3-CH₃-cyclobutyl)CH₂CH₂—, phenyl-CH₂—, (2-F-phenyl)CH₂—,    (3-F-phenyl)CH₂—, (4-F-phenyl)CH₂—, furanyl-CH₂—, thienyl-CH₂—,    pyridyl-CH₂—, 1-imidazolyl-CH₂—, oxazolyl-CH₂—, isoxazolyl-CH₂—,    phenyl-CH₂CH₂—, (2-F-phenyl)CH₂CH₂—, (3-F-phenyl)CH₂CH₂—,    (4-F-phenyl)CH₂CH₂—, furanyl-CH₂CH₂—, thienyl-CH₂CH₂—,    pyridyl-CH₂CH₂—, 1-imidazolyl-CH₂CH₂—, oxazolyl-CH₂CH₂—, or    isoxazolyl-CH₂CH₂—.

In a further preferred embodiment:

-   R³is —(CHR⁷)_(n)—R⁴,-   n is 0 or 1;-   R^(3a) is H, OH, methyl, ethyl, propyl, butyl, methoxy, ethoxy,    propoxy, butoxy, allyl, or 3-buten-1-yl;-   R⁴ is H, OH, OR^(16a),    -   C₁-C₄ alkyl substituted with 0-2 R^(4a),    -   C₂-C₄ alkenyl substituted with 0-2 R^(4a),    -   C₂-C₄ alkynyl substituted with 0-1 R^(4a),    -   C₃-C₆ carbocycle substituted with 0-3 R^(4b),    -   C₆-C₁₀ aryl substituted with 0-3 R^(4b),    -   5 to 6 membered heterocycle containing 1 to 4 heteroatoms        selected from nitrogen, oxygen, and sulphur, wherein said 5 to 6        membered heterocycle is substituted with 0-3 R^(4b);-   R^(4a), at each occurrence, is independently selected from the group    consisting of H, F, Cl, Br, I, CF₃,-   C₃-C₆ carbocycle substituted with 0-3 R^(4b),    -   phenyl substituted with 0-3 R^(4b), or    -   5 to 6 membered heterocycle containing 1 to 4 heteroatoms        selected from nitrogen, oxygen, and sulphur, wherein said 5 to 6        membered heterocycle is substituted with 0-3 R^(4b);    -   R^(4b), at each occurrence, is independently selected from the        group consisting of H, OH, Cl, F, Br, I, CN, NO₂, NR¹⁷R¹⁸, CF₃,        acetyl, SCH₃, S(═O)CH₃, S(═O)₂CH₃, C₁-C₄ alkyl, C₁-C₃ alkoxy,        C₁-C₂ haloalkyl, and C₁-C₂ haloalkoxy;-   R⁵ is H, OR¹⁶;    -   C₁-C₄ alkyl substituted with 0-3 R^(5b),    -   C₂-C₄ alkenyl substituted with 0-3 R^(5b),    -   C₂-C₄ alkynyl substituted with 0-3 R^(5b),-   R^(5a) is H, methyl, ethyl, propyl, or butyl;-   R^(5b), at each occurrence, is independently selected from the group    consisting of:    -   H, methyl, ethyl, propyl, butyl, CF₃, OR¹⁶, Cl, F, Br, I, ═O;    -   C₃-C₆ carbocycle substituted with 0-3 R^(5c),    -   phenyl substituted with 0-3 R^(5c), or    -   5 to 6 membered heterocycle containing 1 to 4 heteroatoms        selected from nitrogen, oxygen, and sulphur, wherein said 5 to 6        membered heterocycle is substituted with 0-3 R^(5c);-   R^(5c), at each occurrence, is independently selected from the group    consisting of H, OH, Cl, F, Br, I, CN, NO₂, NR ¹⁷R¹⁸, CF₃, acetyl,    SCH₃, S(═O)CH₃, S(═O)₂CH₃, C₁-C₄ alkyl, C₁-C₃ alkoxy, C₁-C₂    haloalkyl, and C₁-C₂ haloalkoxy;-   R⁷, at each occurrence, is independently selected from the group    consisting of H, F, CF₃, methyl, and ethyl;-   R¹⁶is H, phenyl, benzyl, C₁-C₄ alkyl, or C₂-C₄ alkoxyalkyl;-   R¹⁷, at each occurrence, is independently selected from the group    consisting of H, C₁-C₄ alkyl, benzyl, phenethyl, (C₁-C₄    alkyl)-C(═O)—, and (C₁-C₄ alkyl)-2(═O)₂—;-   R¹⁸, at each occurrence, is independently selected from the group    consisting of H, OH, C₁-C₄ alkyl, benzyl, phenethyl, (C₁-C₄    alkyl)-C(═O)—, and (C₁-C₄ alkyl)-2(═O)₂—.

In yet another preferred embodiment:

-   Q is —NR¹R²;-   R¹ is OR¹⁶;-   R² is independently selected from the group consisting of H, C₁-C₆    alkyl, C₃-C₁₀ carbocycle, C₆-C₁₀ aryl, and 5 to 10 membered    heterocycle containing I to 4 heteratoms selected from nitrogen,    oxygen, and sulphur;-   R³is —(CR⁷R^(7a))_(n)—R⁴,    -   —(CR⁷R^(7a))_(n)—S—(CR⁷R^(7a))_(m)—R⁴,    -   —(CR⁷R^(7a))_(n)—O—(CR⁷R^(7a))_(m)—R⁴,    -   —(CR⁷R^(7a))_(n)—N(R^(7b))—(CR⁷R^(7a))_(m)—R⁴,    -   —(CR⁷R^(7a))_(n)—S(═O)—(CR⁷R^(7a))_(m)—R⁴,    -   —(CR⁷⁸R^(7a))_(n)—S(═O)₂—(CR⁷R^(7a))_(m)—R⁴,    -   —(CR⁷R^(7a))_(n)—C(═O)—(CR⁷R^(7a))_(m)—R⁴,    -   —(CR⁷R^(7a))_(n)—N(R^(7b))C(═O)—(CR⁷R^(7a))_(m)—R⁴,    -   —(CR⁷R^(7a))_(n)—C(═O)N(R^(7b))—(CR⁷R^(7a))_(m)—R⁴    -   —(CR⁷R^(7a))_(n)—N(R^(7b))S(═O)₂—(CR⁷R^(7a))_(m)—R⁴, or    -   —(CR⁷R^(7a))_(n)—S(═O)₂N(R^(7b))—(CR⁷R^(7a))_(m)—R⁴;-   n is 0, 1, 2, or 3;-   m is 0, 1, 2, or 3;-   R^(3a) is H, OH, C₁-C₄ alkyl, C₁-C₄ alkoxy, C₂-C₄ alkenyl or C₂-C₄    alkenyloxy;-   R⁴ is H, OH, OR^(16a),    -   C₁-C₆ alkyl substituted with 0-3 R^(4a),    -   C₂-C₆ alkenyl substituted with 0-3 R^(4a),    -   C₂-C₆ alkynyl substituted with 0-3 R^(4a),    -   C₃-C₁₀ carbocycle substituted with 0-3 R^(4b),    -   C₆-C₁₀ aryl substituted with 0-3 R^(4b), or    -   5 to 10 membered heterocycle containing 1 to 4 heteroatoms        selected from nitrogen, oxygen, and sulphur, wherein said 5 to        10 membered heterocycle is substituted with 0-3 R^(4b);-   R^(4a), at each occurrence, is independently selected from the group    consisting of H, F, Cl, Br, I, CF₃,    -   C₃-C₁₀ carbocycle substituted with 0-3 R^(4b),    -   C₆-C₁₀ aryl substituted with 0-3 R^(4b), or    -   5 to 10 membered heterocycle containing 1 to 4 heteroatoms        selected from nitrogen, oxygen, and sulphur, wherein said 5 to        10 membered heterocycle is substituted with 0-3 R^(4b);-   R^(4b), at each occurrence, is independently selected from the group    consisting of H, OH, Cl, F, Br, I, CN, NO₂, N¹⁷R¹⁸, CF₃, acetyl,    SCH₃, S(═O)CH₃, C₁-C₆ alkyl, C₁-C₄ alkoxy, C₁-C₆ haloalkyl, C₁-C₄    haloalkoxy, and C₁-C₄ halothioalkyl-S—;-   R⁵ is H, OR¹⁶,    -   C₁-C₆ alkyl substituted with 0-3 R^(5b),    -   C₁-C₆ alkoxy substituted with 0-3 R^(5b),    -   C₂-C₆ alkenyl substituted with 0-3 R^(5b),    -   C₂-C₆ alkynyl substituted with 0-3 R^(5b),    -   C₃-C₁₀ carbocycle substituted with 0-3 R^(5c),    -   C₆-C₁₀aryl substituted with 0-3 R^(5c), or    -   5 to 10 membered heterocycle containing 1 to 4 heteroatoms        selected from the group consisting of nitrogen, oxygen, and        sulphur, wherein said 5 to 10 membered heterocycle is        substituted with 0-3 R^(5c);-   R^(5a) is H, OH, C₁-C₄ alkyl, C₁-C₄ alkoxy, C₂-C₄ alkenyl, or C₂-C₄    alkenyloxy;-   R^(5b), at each occurrence, is independently selected from the group    consisting of:    -   H, C₁-C₆ alkyl, CF₃, OR¹⁶, Cl, F, Br, I, ═O, CN, NO₂, NR¹⁷R¹⁸;    -   C₃-C₁₀ carbocycle substituted with 0-3 R^(5c),    -   C₆-C₁₀ aryl substituted with 0-3 R^(5c), or    -   5 to 10 membered heterocycle containing 1 to 4 heteroatoms        selected from nitrogen, oxygen, and sulphur, wherein said 5 to        10 membered heterocycle is substituted with 0-3 R^(5c);-   R^(5c), at each occurrence, is independently selected from the group    consisting of H, OH, Cl, F, Br, T, CN, NO₂, NR¹⁷R¹⁸, CF₃, acetyl,    SCH₃, S(═O)CH₃, S(═O)₂CH₃,    -   C₁-C₆ alkyl, C₁-C₄ alkoxy, C₁-C₄ haloalkyl,    -   C₁-C₄ haloalkoxy, and C₁-C₄ halothioalkyl-S—;-   R⁷, at each occurrence, is independently selected from the group    consisting of H, OH, Cl, F, Br, I, CN, NO₂, CF₃, phenyl and C₁-C₄    alkyl;-   R^(7a), at each occurrence, is independently selected from the group    consisting of H, OH, Cl, F, Br, I, CN, NO₂, CF₃, and C₁-C₄ alkyl;-   R^(7b) is independently selected from the group consisting of H and    C₁-C₄ alkyl;-   R¹⁶ is H, phenyl, benzyl, C₁-C₆ alkyl, C₂-C₆ alkoxyalkyl, or C₃-C₆    cycloalkyl;-   R^(16a) is H, phenyl, benzyl, or C₁-C₄ alkyl;-   R¹⁷, at each occurrence, is independently selected from the group    consisting of H, C₁-C₆ alkyl, benzyl, phenethyl, (C₁-C₆    alkyl)-C(═O)—, and (C₁-C₆ alkyl)-S(═O)₂—;-   R¹⁸, at each occurrence, is independently selected from the group    consisting of H, OH, C₁-C₆ alkyl, benzyl, phenethyl, (C₁-C₆    alkyl)-C(═O)—, and (C₁-C₆ alkyl)-S(═O)₂—.    Definition

The term “β-amyloid peptide” refers to a 39-43 amino acid peptide havinga molecular weight of about 4.2 kD, which peptide is substantiallyhomologous to the form of the protein described by Glenner, et al.(Biochem. Biophys. Res. Commun., 120:885-890 (1984)) including mutationsand post-translational modifications of the normal β-amyloid peptide. Inwhatever form, the β-amyloid peptide is approximately a 39-43 amino acidfragment of a large membrane-spanning glycoprotein, referred to as theβ-amyloid precursor protein (APP). Its 43-amino acid sequence is:

1

Asp Ala Glu Phe Arg His Asp Ser Gly Tyr

11

Glu Val His His Gln Lys Leu Val Phe Phe

21

Ala Glu Asp Val Gly Ser Asn Lys Gly Ala

31

Ile Ile Gly Leu Met Val Gly Gly Val Val

41

Ile Ala Thr (SEQ ID NO: 1)

or a sequence which is substantially homologous thereto.

“Alkyl” refers to monovalent alkyl groups preferably having from 1 to 10carbon atoms and more preferably 1 to 6 carbon atoms. This term isexemplified by groups such as methyl, ethyl, n-propyl, iso-propyl,n-butyl, iso-butyl, n-hexyl, and the like. The use of the notation “C”followed by a numerical range preceding a defined term, indicates arange of atoms intended to add further to the definition. e.g.,(C₁₋₆)alkyl defines an alkyl group having from 1 to 6 (inclusive) carbonatoms.

Unless otherwise constrained by a limitation of the alkyl group, alkylcan optionally be substituted with from 1 to 3 substituents selectedfrom the group consisting of hydroxy, (C₁₋₃) alkoxy, (C₁₋₃)alkylthioxy,halo, acyl, acyloxy, phenyl optionally substituted with 1 to 2 haloatoms and trifluoromethyl.

“Arylalkyl” refers to aryl-alkylene-groups preferably having from 1 to 6carbon atoms in the alkylene moiety and from 6 to 10 carbon atoms in thearyl moiety. Such arylalkyl groups are exemplified by benzyl, phenethyland the like.

“Alkoxy” refers to the group “alkyl-O—” where alkyl is as definedherein. Preferred alkoxy groups include, by way of example, methoxy,ethoxy, n-propoxy, iso-propoxy, n-butoxy, tert-butoxy, sec-butoxy,n-pentoxy, n-hexoxy, 1,2-dimethylbutoxy, and the like.

“Alkenyl” refers to alkenyl groups preferably having from 2 to 10 carbonatoms and more preferably 2 to 6 carbon atoms and having at least 1 andpreferably from 1-2 sites of alkenyl unsaturation. Preferred alkenylgroups include ethenyl (—CH═CH₂), n-propenyl (—CH₂CH═CH₂), iso-propenyl(—C(CH₃)═CH₂), but-2-enyl (—CH₂CH═CHCH₃) and the like.

“Alkynyl” refers to alkynyl groups preferably having from 2 to 10 carbonatoms and more preferably 2 to 6 carbon atoms and having at least 1 andpreferably from 1-2 sites of alkynyl unsaturation. Preferred alkynylgroups include ethynyl (—C≡CH), propargyl (—CH₂-C≡CH) and the like.

“Acyl” refers to the groups alkyl-C(O)—, aryl-C(O)—, andheteroaryl-C(O)— where alkyl, aryl and heteroaryl are as defined herein.

“Acylamino” refers to the group —C(O)NRR where each R is independentlyhydrogen or alkyl where alkyl is as defined herein.

“Aminoacyl” refers to the group —NRC(O)R where each R is independentlyhydrogen or alkyl where alkyl is as defined herein.

“Acyloxy” refers to the groups alkyl-C(O)O—, aryl-C(O)O—,heteroaryl-C(O)O—, and heterocyclic-C(O)O— where alkyl, aryl, heteroaryland heterocyclic are as defined herein.

“Aryl” refers to an unsaturated aromatic carbocyclic group of from 6 to14 carbon atoms having a single ring (e.g., phenyl) or multiplecondensed rings (e.g., naphthyl or anthryl). Preferred aryls includephenyl, naphthyl and the like.

Unless otherwise constrained by the definition for the aryl substituent,such aryl groups can optionally be substituted with from 1 to 3substituents selected from the group consisting of hydroxy, acyl,acyloxy, alkyl, alkoxy, alkenyl, alkynyl, amino, aminoacyl, aryl,aryloxy, carboxyl, alkoxycarbonyl, acylamino, cyano, halo, nitro,heteroaryl, trihalomethyl and the like. Preferred substituents includealkyl, alkoxy, halo, cyano, nitro, trihalomethyl, and thioalkoxy.

“Aryloxy” refers to the group aryl-O— wherein the aryl group is asdefined above including optionally substituted aryl groups as alsodefined above.

The terms “amide” and “amido” refer to a functional group containing acarbon atom double-bonded to an oxygen atom and additionally singlybonded to a nitrogen atom [—C(O)—N]. “Primary” amide describes anunsubstituted amide group [—C(O)—NH₂]. “Secondary” and “tertiary” amidesare amides in which nitrogen is substituted with one and twonon-hydrogen groups respectively.

“Cycloalkyl” refers to cyclic alkyl groups of from 3 to 10 carbon atomshaving a single cyclic ring or multiple condensed rings which can beoptionally substituted with from 1 to 3 alkyl groups. Such cycloalkylgroups include, by way of example, single ring structures such ascyclopropyl, cyclobutyl, cyclopentyl, cyclooctyl, 1-methylcyclopropyl,2-methylcyclopentyl, 2-methylcyclooctyl, and the like, or multiple ringstructures such as adamantanyl, and the like.

“Cycloalkenyl” refers to cyclic alkenyl groups of from 4 to 8 carbonatoms having a single cyclic ring and at least one point of internalunsaturation which can be optionally substituted with from 1 to 3 alkylgroups. Examples of suitable cycloalkenyl groups include, for instance,cyclobut-2-enyl, cyclopent-3-enyl, cyclooct-3-enyl and the like.

“Halo” or “halogen” refers to fluoro, chloro, bromo and iodo andpreferably is either chloro or fluoro.

“Heterocycle” or “heterocyclic” refers to a monovalent saturated orunsaturated group having a single ring or multiple condensed rings, from1 to 8 carbon atoms and from 1 to 4 hetero atoms selected from nitrogen,sulfur or oxygen within the ring.

Unless otherwise constrained by the definition for the heterocyclicsubstituent, such heterocyclic groups can be optionally substituted with1 to 3 substituents selected from the group consisting of alkyl, alkoxy,aryl, aryloxy, halo, nitro, heteroaryl, thioalkoxy, thioaryloxy and thelike. Such heterocyclic groups can have a single ring (e.g., piperidinylor tetrahydrofuryl) or multiple condensed rings (e.g., indolinyl,dihydrobenzofuran or quinuclidinyl). Preferred heterocycles includepiperidinyl, pyrrolidinyl and tetrahydrofuryl.

Examples of heterocycles and heteroaryls include, but are not limitedto, furan, thiophene, thiazole, oxazole, pyrrole, imidazole, pyrazole,pyridine, pyrazine, pyrimidine, pyridazine, indolizine, isoindole,indole, indazole, purine, quinolizine, isoquinoline, quinoline,phthalazine, naphthylpyridine, quinoxaline, quinazoline, cinnoline,pteridine, carbazole, carboline, phenanthridine, acridine,phenanthroline, isothiazole, phenazine, isoxazole, phenoxazine,phenothiazine, imidazolidine, imidazoline, piperidine, piperazine,pyrrolidine, indoline and the like.

“Thiol” refers to the group —SH.

“Thioalkoxy” refers to the group —S-alkyl.

“Thioaryloxy” refers to the group aryl-S— wherein the aryl group is asdefined above including optionally substituted aryl groups as alsodefined above.

“Pharmaceutically acceptable salt” refers to pharmaceutically acceptablesalts of a compound of Formula I which salts are derived from a varietyof organic and inorganic counter ions well known in the art and include,by way of example only, sodium, potassium, calcium, magnesium, ammonium,tetraalkylammonium, and the like; and when the molecule contains a basicfunctionality, salts of organic or inorganic acids, such ashydrochloride, hydrobromide, tartrate, mesylate, acetate, maleate,oxalate and the like.

“Privileged structures” are defined in J. Med. Chem. 41: 3103 (1998);they are derivatives of frequently occurring hydrophobic double-ringstructure units, including, but not limited to benzodiazepines,spiroindanylpiperidine, etc. It is found that the presence ofhydrophobic double-ring systems contributes to the receptor affinity ofmany biogenic amine antagonists. It is suggested that this motif bind toaccessory binding sites of a predominantly hydrophobic nature locatednext to the receptor for the corresponding agonist.

Synthesis and Preparation of Compounds Having Formula I

The compounds of the present invention can be prepared in a number ofways known to one skilled in the art of organic synthesis. The compoundsof the present invention can be synthesized using the methods describedbelow, together with synthetic methods known in the art of syntheticorganic chemistry, or variations thereon as appreciated by those skilledin the art. Preferred methods include, but are not limited to, thosedescribed below. All references cited herein are hereby incorporated intheir entirety by reference.

The novel compounds of this invention may be prepared using thereactions and techniques described in this section. The reactions areperformed in solvents appropriate to the reagents and materials employedand are suitable for the transformations being effected. Also, in thedescription of the synthetic methods described below, it is to beunderstood that all proposed reaction conditions, including choice ofsolvent, reaction atmosphere, reaction temperature, duration of theexperiment and workup procedures, are chosen to be the conditionsstandard for that reaction, which should be readily recognized by oneskilled in the art. It is understood by one skilled in the art oforganic synthesis that the functionality present on various portions ofthe molecule must be compatible with the reagents and reactionsproposed. Such restrictions to the substituents which are compatiblewith the reaction conditions will be readily apparent to one skilled inthe art and alternate methods must then be used.

Appropriate succinic acids, succinate esters and derivatives can beprepared according to WO 00/38618 and Becker, et al. (Synlett, 1993,pl38-138.) A succinic acid or succinate ester can be coupled to anappropriate amino moiety of an intermediate using methods commonly usedin peptide syntheses, such as DCC, EDCI, CDI, BOP, PyBOP, HOAT, HATU,HBTU, POCI₃, and phenyl ester mediated coupling, for example, asdescribed in A. R. Chamberlin, Chem. Rev. 97:2243-2266 (1997) and WO00/38618.

Construction of Succinoyl Amino Pyrazoles

A variety of substituted succinoyl amino pyrazoles can be prepared usingthe corresponding carboxylic acids in this fashion.

Method A

A solution of 0.11 mole of substituted phenylacetic acid in 200 mL ofMeOH was prepared. Gaseous HCl was bubbled through the reaction solutionfor 4 min. After bubbling HCl_((gas)), the solution was stirred at roomtemperature for 17 hrs. The solvent was then stripped off by rotaryevaporation. The remaining liquid was quenched with saturatedNaHCO_(3(aq)) to ˜pH 8 and extracted with EtOAc (3×100 mL). The combinedorganic extracts were dried over MgSO₄ and vacuum filtered. The filtratewas rotary evaporated and dried under vacuum to afford a clear colorlessliquid as product 1.Method B

A suspension of 0.42 mole (4.0 eq.) of NaH in 500 mL of dry DMF wascooled to −10° C. and 0.11 moles (1.0 eq.) of phenylacetic acid methylester 1 was added. The reaction mixture was stirred for 10 min followedby the careful addition of 0.42 moles (4.0 eq.) of methyl iodide. Afterstirring the reaction mixture, as bath warmed to room temperature, for16 hrs, 100 mL of water was added followed by 200 mL of 0.1 M HCl. Thesolution was extracted with EtOAc (3×200 mL). The combined organicextracts were washed with 0.1 M HCl (2×100 mL), followed by drying overMgSO₄ and vacuum filtering. The filtrate was rotary evaporated and thecrude mixture was flash chromatographed on silica using 5% EtOAc/hexanesas eluent to afford a light yellowish liquid as theα,α-dimethyl-phenylacetic acid methyl ester 2 (69-96% yield after 2steps).Method C

A solution of 0.10 mole (1 eq.) of α,α-dimethylphenylacetic acid methylester 2 in 150 mL of MeOH and 50 mL of water was added 1.02 mole (10. 1eq.) of KOH pellets. After stirring at room temperature for 3.5 days,the methanol was stripped off by rotary evaporation. To the residualliquid was added 100 mL of water and enough concentrated HCl to bring to˜pH 3. The aqueous solution was extracted with Et₂O (3×100 mL). Thecombined organic layers were dried over MgSO₄ and vacuum filtered. Thefiltrate was rotary evaporated and dried under vacuum to give a whitesolid as α,α-dimethylphenylacetic acid 3 (87-89%).Method D

In a dried 250 mL round bottom flask, a solution of 0.088 mole (1.0 eq.)of α,α-dimethylphenylacetic acid 3 in 100 mL of dry tetrahydrofuran THFwas prepared. To the reaction solution was added 0.114 mole (1.3 eq.) ofN,N′-carbonyldiimidazole. The reaction solution was stirred for 1 hr atroom temperature.

In a separate 1 L round bottom flask, a solution of 0.264 mole (3.0 eq.)of cyanoacetic acid in 600 mL of dry THF was cooled to −78 ° C. and0.526 mole (6.0 eq.) of isopropylmagnesium chloride was added. Thereaction mixture was stirred in bath for 25 min and the imidazolidesolution prepared via above method was added. After addition, thereaction mixture was stirred, as bath warned to room temperature, for 17hrs. At that time, 400 mL of water was added followed by enoughconcentrated acetic acid to bring to ˜pH 5. The acidified solution wasextracted with Et₂O (3×100 mL). The combined organic extracts were driedover MgSO₄ and vacuum filtered. The filtrate was concentrated by rotaryevaporation. The crude material was flash chromatographed on silica with20% EtOAc/hexanes to give a yellowish oil as ketonitrile product 4(46-67%).Method E

A solution of 0.088 (1.0 eq.) mole of ketonitrile 4, 0.353 mole (4.0eq.) of tert-butylhydrazine, and 0.44 mole (5.0 eq.) of triethylamine in100 mL of absolute ethanol was refluxed for 4 days. After cooling toroom temperature, the reaction solution was rotary evaporated. Theresidue was taken up in 100 mL of water and was extracted with EtOAc(3×100 mL). The combined organic extracts were dried over MgSO₄ andvacuum filtered. The filtrate was rotary evaporated. The residual crudematerial was flash chromatographed on silica with 10% EtOAc/hexanes toafford amino pyrazole 5 (50-87%).

Method F

General Procedure for POCl₃ Coupling.

A solution of 2.3 mmole (1.0 eq) of amine (pyrazoles, thiadiazole,anilines) and 2.3 mmole (1.0 eq) of succinic acid in 8.0 mL of drypyridine was stirred at −10 ° C. as 2.6 mmole (1. 1 eq) of POCl₃ wasadded dropwise. After 15 min, the reaction mixture was poured into 125mL of 1M HCl and extracted with EtOAc. The organic layer was dried overMgSO₄, filtered and the solvent removed by rotary evaporation.Purification of the material on silica gel using 3:7 EtOAc-hexanes aseluant afforded 1.4 mmole (59%) of product.

Method G

A solution of 2.0 mmoles (1.0 eq.) of N-tert-butyl protected pyrazole 6in 10 mL of formic acid is refluxed for 15 min. The reaction solution iscooled to room temperature and is added dropwise to saturatedNaHCO_(3(aq)). After ensuring ˜pH 8, the quenched solution is extractedwith EtOAc (3×100 mL). The combined organic extracts are rotaryevaporated. The residue is dissolved in 10 mL of MeOH and 0.80 mmole(0.4 eq.) of LiOH.H₂O added. After stirring the mixture at roomtemperature for 20 min, the solvent is rotary evaporated. The residue istaken up in 40 mL of water and 2 mL of 1 M HCl is added, followed byenough saturated NaHCO_(3(aq)) to raise to pH 8. The mixture isextracted with EtOAc (3×70 mL). The combined organic extracts are driedover ˜MgSO₄ and vacuum filtered. The filtrate is rotary evaporated andthe crude material is flash chromatographed on silica with 3%MeOH/CH₂Cl₂ to yield the desired product.Construction of Succinoyl Amino Thiadiazoles

A variety of 5′ subtituted thiadiazoles can be prepared via thecorresponding substituted carboxylic acids.

Method I

To a stirred solution of carboxylic acid (42.4 mmol) in anhydrousdichloromethane (40 ml) was added oxalyl chloride (3.70 ml, 42.4 mmol),followed by addition of 0.5 ml of DMF. The reaction mixture was stirreduntil bubbling ceased.

The reaction mixture was evaporated to dryness, the residue wasdissolved in anhydrous THF and was added dropwise to a suspension ofthiosemicarbazide (7.73 g, 84.8 mmol) in anhydrous THF cooled in anice-water bath. The reaction mixture was allowed to warm to roomtemperature and stirred for 18 h. The reaction mixture was filtered andconcentrated to yield the desired product.

Method J

The product from Method 1 (4.7466 g, 20 mmol), methanesulfonic acid (2ml, 30 mmol) and toluene (60 ml) were refluxed for 5 h, and allowed tocool down. The crystals were filtered off, and washed with toluenefollowed by diethyl ether. The resulting solid was placed in a beaker,and treated with concentrated ammonium hydroxide. The precipitate wasfiltered off, washed with water, and air-dried to yield the desiredproduct.Construction of Succinoyl Derivatives of Privileged Structures

The definition of Privileged structures can be found in J. Med. Chem.41: 3103 (1998). The succinoyl derivatives of privileged structures ofthis invention include the derivatives of the privileged structuresZ1-Z76 listed at page 391 in J. Comb. Chem., 1: 388-396 (1999),excluding lactams (Z29) and benzodiazepine (Z32). Also of interest arethe succinoyl derivatives of the following privileged structures:

*Amine is commercially available.

Using a variety of privileged structures, the following types ofcompounds are prepared.

Method K

To a round bottom flask equipped with a magnetic stirbar and N₂ inlet,DMF (30 mL), succinoyl acid (10 mmol), and the amine (10 mmol) areadded. The mixture is cooled to 0° C., followed by the addition oftriethylamine (TEA), 30 mmol and 1-hydroxybenzotriazole hydrate (HOBT),26 mmol. The mixture is stirred at 0° C. for 30 min followed by theaddition of the 1-ethyl-3-(3′-Dimethylaminopropyl)carbodiimidehydrochloride (EDCl), 13 mmol. The reaction mixture is allowed to warmto room temperature and stirred under N₂ overnight. The reaction mixtureis transferred to a separatory funnel and diluted with 30 ml H₂O andextracted with 60 ml ethylacetate. The organic is backwashed by 2×60 mldilute citric acid, followed by 2×60 ml saturated sodium bicarbonate,followed by 1×60 ml brine and finally dried over MgSO₄, and concentratedin vacuo to yield the desired product.

Construction of Succinoyl Amino Acid Esters

Using a variety of amino acids esters (natural, unnatural) the followingtypes of compounds can be prepared.

Method L

To a round bottom flask equipped with a magnetic stirbar and N₂ inlet,DMF (30 mL), succinic acid (10 mmol), and the amino acid ester (10 mmol)are added. The mixture is cooled to 0° C., followed by the addition oftriethylamine (TEA), 30 mmol, and 1-hydroxybenzotriazole hydrate (HOBT),26 mmol. The mixture is stirred at 0° C. for 30 min followed by theaddition of the 1-ethyl-3-(3′-Dimethylaminopropyl)carbodiimidehydrochloride (EDCl), 13 mmol. The reaction mixture is allowed to warmto room temperature and stirred under N₂ overnight. The reaction mixtureis transferred to a separatory funnel and diluted with 30 ml H₂O andextracted with 60 ml ethylacetate. The combined organic layers arebackwashed by 2×60 ml dilute citric acid, followed by 2×60 ml saturatedsodium bicarbonate, followed by 1×60 ml brine and finally dried overMgSO₄, and concentrated in vacuo to yield the desired product.

Construction of Succinoyl Anilines

Using a variety of substituted anilines the following types of compoundscan be prepared.

Method M

To a round bottom flask equipped with a magnetic stirbar and N₂ inletwas added DMF (30 mL), the hydroxyalkanoic acid (10 mmol), and theaniline (10 mmol) are added. The mixture is cooled to 0° C., followed bythe addition of triethylamine (TEA), 30 mmol and 1-hydroxybenzotriazolehydrate (HOBT), 26 mmol. The mixture is stirred at 0° C. for 30 minfollowed by the addition of the1-ethyl-3-(3′-Dimethylaminopropyl)carbodiimide hydrochloride (EDCl), 13mmol. The reaction mixture is allowed to warm to room temperature andstirred under N₂ overnight. The reaction mixture is transferred to aseparatory funnel and diluted with 30 ml H₂O and extracted with 60 mlethylacetate. The combined organic layers are backwashed by 2×60 mldilute citric acid, followed by 2×60 ml saturated sodium bicarbonate,followed by 1×60 ml brine and finally dried over MgSO₄, and concentratedin vacuo to yield the desired product.Construction of Succinoyl Amino Acid Amides

Using a variety of amino acids (natural, unnatural) and a variety offunctionalized amines, succinoyl amino acid amides can be prepared. Thefollowing three amines (NR¹²NR¹³) with norleucine as the amino acid(—NHCHR¹¹CO—) are preferred compounds.

Method N

To a round bottom flask equipped with a magnetic stirbar and N₂ inletwas added DMF (30 mL), Boc-Ala-OH, 10 mmol, and the amine, 10 mmol. Themixture was cooled to 0° C., followed by the addition of triethylamine(TEA), 30 mmol and 1-hydroxybenzotriazole hydrate (HOBT), 26 mmol. Themixture was stirred at 0° C. for 30 min followed by the addition of the1-ethyl-3-(3′-Dimethylaminopropyl)carbodiimide hydrochloride (EDCl, 13mmol. The reaction mixture was allowed to warm to room temperature andstirred under N₂ overnight. The reaction mixture was transferred to aseparatory funnel and diluted with 30 ml H₂O and extracted with 60 mlethylacetate. The combined organic layers were backwashed 2×60 ml dilutecitric acid, followed by 2×60 ml saturated sodium bicarbonate, followedby 1×60 ml brine and finally dried over MgSO₄, and concentrated in vacuoto yield the desired material.

Method O

Trifluoroacetic acid (TFA), 15 mL was added to carbamate (10 mmol) andstirred at room temperature for 30 minutes. The reaction mixture wasconcentrated in vacuo to give a yellow oil. To this, DMF (30 ml) andhydroxyalkanoic acid (10 mmol) were added. The mixture was cooled to 0°C., followed by the addition of triethylamine (TEA), 30 mmol, and1-hydroxybenzotriazole hydrate (HOBT), 26 mmol. The mixture was stirredat 0° C. for 30 min followed by the addition of the1-ethyl-3-(3′-Dimethylaminopropyl)carbodiimide hydrochloride (EDCl), 13mmol. The reaction mixture was allowed to warm to room temperature andstirred under N₂ overnight. The reaction mixture was transferred to aseparatory funnel and diluted with 30 ml H₂O and extracted with 60 mlethyl acetate. The combined organic layers were backwashed by 2×60 mldilute citric acid, followed by 2×60 ml saturated sodium bicarbonate,followed by 1×60 ml brine and finally dried over MgSO₄, and concentratedin vacuo to yield the desired product.Construction of Succinoyl Amino Acid Alcohols and Ketones

Using a variety of amino acid aldehydes (natural, unnatural) and avariety Grignard reagents (prepared and purchased), succinoyl amino acidalcohols and succinoyl amino acid ketones are prepared. The followingamino acid alcohol and ketone structures are preferred.

Method P

Amino acid aldehyde (100 M %) was suspended in THF and cooled to 0° C.The Grignard reagent was added dropwise (250 M %) and all was allowed towarm to room temperature and stir for 4 hours. The reaction was quenchedwith dilute aqueous citric acid then extracted with ethyl acetate (3×).The combined organic layers were washed with aqueous NaHCO₃ (2×), dried(MgSO₄), then solvents evaporated in vacuo. Flash chromatography yieldedthe desired product.

Method Q

The Dess-Martin reagent, 1,1,1triacetoxy-1,1-Dihydro-1,2-Benziodoxol-3(1H)-one, 300M %) was added to asolution of CH₂Cl₂ (50 mL) and the starting alcohol (100M %). Thisinitial mixture was cloudy so enough DMF was added to make the solutionhomogeneous. All was stirred for 8 hours at which time the reaction waspoured into a saturated aqueous solution of NaCl, and extracted withEtOAc (3×). The combined organic layers were washed with aqueous NaHCO₃(2×), brine (1×), dried (MgSO₄), then solvents evaporated in vacuo.Flash chromatography yielded the desired product.

Construction of Succinoyl Amino Hydantoin

Preparation of N-Amino-Hydantoin

The widely used coupling method in Fmoc protected peptide synthesis isthe active ester method, either by in-situ generation, or addition ofpreformed active ester. The commonly used activated esters are thepentafluorophenyl (OPfp) and 3-hydroxy-2,3-dihydro-4-oxo-benzotriazone(Odhbt). In the presence of HOBt, the rate of reaction is very rapid andefficient with minimal side products. More recently,1-hydroxy-7-azabenzotriazole (HOAt) and its corresponding uronium saltanalog O-(7-azabenzotrizol-1-yl)-1,1,3,3, tetramethyluroniumhexafluorophosphate (HATU) have been developed and shown to have agreater catalytic activity than their HOBt and HBTU counterparts,resulting in enhanced coupling yields, shorter coupling times, andgreater reduction of racemization. Consequently, these reagents aresuitable for coupling sterically hindered amino acids and thereby ensuregreater success in the synthesis of difficult peptides andpeptidomimetics containing amide bonds. The method utilizing HOAt/HATUfor active ester formation is a preferred method of synthesizing N-aminohydantoin.

EXAMPLES

The following examples further illustrate the present invention. Theseexamples are intended merely to be illustrative of the present inventionand are not to be construed as being limiting.

Example 1 N3-Amino-5,5′-diphenyl-imidazolidine-2,4-dione

20 g (79.3 mmol) of 5,5′-diphenylydantoin was suspended in 32 mL (0.63mol) hydrazine monohydrate and refluxed for 7 hours. The reactionmixture was allowed to cool to room temperature. The productcrystallized as white precipitate and was separated from the motherliquor via filtration through a glass frit and washed three times withwater. The crude material was recrystallized twice from a 9:1ethanol/water mixture. Yield: 12.6 g (60% of Th.).

LC/MS showed MH⁺ at 268.2 (exp. 268.2) t_(R)=1.38 min, CH₃CN/H₂Ogradient, [mobile phase A: 0.05% TFA in H20; mobile phase B 0.035% TFQin CH3CN, column 4.6×50 mm ODC-A: S-5, gradient elution 99:1 A:B to 1:99A:B, 5.0 min., 3.5 mL/min flow rate].

Example 2 N3-Amino-5-benzyl-imidazolidine-2,4-dione

660 mg (4.0 mmol) of L-phenylalanine and 665 mg (5.0 mmol) oftert-butyl-carbazate) were suspended in 7.5 mL quinoline and heated toreflux (˜240° C.) for 4 h. The reaction mixture was cooled to roomtemperature and 10 mL diethylether and 30 mL hexanes were added. Theprecipitated solid was recrystallized from 2-propanol/water to afford 88mg (10% of Th.) product.

LC/MS showed MH⁺ at 205 (exp. 205) t_(R)=1.35 min, CH₃CN/H₂O gradient,[mobile phase A: 0.05% TFA in H20; mobile phase B 0.035% TFQ in CH3CN,column 4.6×50 mm ODC-A: S-5, gradient elution 99:1 A:B to 1:99 A:B, 5.0min., 3.5 mL/min flow rate].

Example 3 N3-Amino-5-phenyl-imidazolidine-2,4-dione

605 mg (4.0 mmol) of L-phenylglycine and 665 mg (5.0 mmol) oftert-butyl-carbazate were suspended in 7.5 mL quinoline (redistilled)and heated to reflux (˜240° C.) for 2.5 h. The reaction mixture wascooled to room temperature and diethylether and hexanes were added,resulting in separation of an oil, which solidified on standingovernight. The product was recrystallized from methanol/hexane to afford171 mg (23% of Th.) product.

LC/MS showed MH⁺ at 205 (exp. 205) t_(R)=1.35 min, CH₃CN/H₂O gradient,[mobile phase A: 0.05% TFA in H20; mobile phase B 0.035% TFQ in CH3CN,column 4.6×50 mm ODC-A: S-5, gradient elution 99:1 A:B to 1:99 A:B, 5.0min., 3.5 mL/min flow rate].

Example 4 N3-Amino-N1-phenyl-imidazolidine-2,4-dione

Step 1: Ethyl N-phenylglycinate ethyl carbamate

N-Phenylglycine ethyl ester and 3.0 mL ethylchloroformate were suspendedin 100 mL of 2N Na₂CO₃ and stirred at 50° C. for 15 min. An additional3.0 mL of ethylchloroformate was added and the reaction stirred for 30min. Diethylether was added, the organic layer was separated and washedsequentially with 10% aqueous citric acid and 1N NaHCO₃ and dried overMgSO₄. The solvents were evaporated and the remaining oil was driedunder high vacuum to give the intermediate carbamate. Yield: 3.8g (92%of Th.).

Step 2: 3-Amino-1-phenyl-imidazolidine-2,4-dione

The carbamate prepared above (3.8g, 15.4 mmol) was dissolved in 6 mL of1-butanol. Hydrazine monohydrate (1.0 mL, 20 mmol) was added and thereaction mixture was refluxed for 3 h. The product crystallized uponcooling and was recrystallized from ethanol/water as white needles.Yield: 903mg (29% of Th.)

LC/MS showed MH⁺ at 192.2 (exp. 192) t_(R)=1.75 min, CH₃CN/H₂O gradient,[mobile phase A: 0.05% TFA in H20; mobile phase B 0.035% TFQ in CH3CN,column 4.6×50 mm ODC-A: S-5, gradient elution 99:1 A:B to 1:99 A:B, 5.0min., 3.5 mL/min flow rate].

Example 5N3-[(2′S)-Aminopropionamide)-5,5′-diphenyl-imidazolidine-2,4-dione

This example shows representative procedures for incorporation ofamino-acids (—NH—CH(R₁)—C(O)—).

2.42 g (9 mmol) of N3-amino-5,5′-diphenyi-imidazoline-2,4-dione and 3.12g (9.44 mmol) of (L)-Fmoc-Ala-Cl were suspended in 60 mL ofdichloromethane. The reaction suspension turned clear within minutes.1.6 mL (9.44 mmol) of diisopropylethylamine was added and the reactionwas stirred under nitrogen for 1 h. Following coupling, the amine wasdeprotected in situ by addition of 20 mL of diethylamine and stirringfor another hour at room temperature. The solvents and the excess basewere evaporated, and the residual oil was dissolved in dichloromethaneand purified by flash-chromatography using a gradient elution ofchloroform/methanol (15:1 to 4:1), affording 2.1 g (6.2 mmol, 68% ofTh.) of free amine.

LC/MS showed MH⁺ at 339.2 (exp. 339) t_(R)=2.2 min, CH₃CN/H₂Ogradient[mobile phase A: 0.05% TFA in H20; mobile phase B 0.035% TFQ inCH3CN, column 4.6×50 mm ODC-A: S-5, gradient elution 99:1 A:B to 1:99A:B, 5.0 min., 3.5 mL/min flow rate].

¹H-NMR (300 MHz, d₆-DMSO) 9.25 (s,1H, NH); 6.9 (m,10H); 2.35 (s,1H); 1.9(m, 2H, NH₂); 0.8 (d, 3H).

Example 6N3-[(2′S)-Aminophenylacetamide)-5,5′-diphenyl-imidazolidine-2,4-dione

Step 1: 2.5 g (9.35 mmol) ofN3-amino-5,5′-diphenyl-imidazoline-2,4-dione and 4.3 g (7.5 mmol) of(L)-Boc-phenylglycine were suspended in 125 mL dichloroethane. HOAt(2.55 g, 18.75 mmol), HATU (7.12 g, 18.74 mmol) anddilsopropylethylamine (6.5 mL, 37.3 mmol) were added and the reactionwas refluxed under nitrogen for 16 h. The reaction mixture was dilutedwith EtOAc and washed sequentially with 10% citric acid and brine.Concentration in vacuo gave a thick oil, which was partially purified byflash chromatography using a gradient elution (20-40% EtOac/hexanes). 2g of pure product was taken forward.Step 2: The Boc-protected amine (2.0 g, 4 mmol) was dissolved in 80 mLof dichloromethane and cooled to 0° C. HCl (gas) was bubbled through thesolution for 10 minutes. The flask was capped and allowed to warm to rtwhile stirring overnight. The reaction mixture was sparged with N₂ for20 minutes, then filtered to collect the precipitated aminehydrochloride salt (509 mg, 29%).

LC/MS showed MH⁺ at 401.4 (exp. 401) t_(R)=2.47 min, CH₃CN/H₂O gradient,[mobile phase A: 0.05% TFA in H20; mobile phase B 0.035% TFQ in CH3CN,column 4.6×50 mm ODC-A: S-5, gradient elution 99:1 A:B to 1:99 A:B, 5.0min., 3.5 mL/min flow rate]

Pharmaceutical Formulations

When employed as pharmaceuticals, the compounds of Formula I are usuallyadministered in the form of pharmaceutical compositions. These compoundscan be administered by a variety of routes including oral, rectal,transdermal, subcutaneous, intravenous, intramuscular, and intranasal.These compounds are effective as both injectable and oral compositions.Such compositions are prepared in a manner well known in thepharmaceutical art and comprise at least one active compound.

This invention also includes pharmaceutical compositions that contain,as the active ingredient, one or more of the compounds of Formula I, ora pharmaceutically accepted form or prodrug thereof, associated withpharmaceutically acceptable carriers. In making the compositions of thisinvention, the active ingredient is usually mixed with an excipient,diluted by an excipient or enclosed within such a carrier which can bein the form of a capsule, sachet, paper or other container. When theexcipient serves as a diluent, it can be a solid, semi-solid, or liquidmaterial, which acts as a vehicle, carrier or medium for the activeingredient. Thus, the compositions can be in the form of tablets, pills,powders, lozenges, sachets, cachets, elixirs, suspensions, emulsions,solutions, syrups, aerosols (as a solid or in a liquid medium),ointments containing, for example, up to 10% by weight of the activecompound, soft and hard gelatin capsules, suppositories, sterileinjectable solutions, and sterile packaged powders.

In preparing a formulation, it may be necessary to mill the activecompound to provide the appropriate particle size prior to combiningwith the other ingredients. If the active compound is substantiallyinsoluble, it ordinarily is milled to a particle size of less than 200mesh. If the active compound is substantially water soluble, theparticle size is normally adjusted by milling to provide a substantiallyuniform distribution in the formulation, e.g. about 40 mesh.

Some examples of suitable excipients include lactose, dextrose, sucrose,sorbitol, mannitol, starches, gum acacia, calcium phosphate, alginates,tragacanth, gelatin, calcium silicate, microcrystalline cellulose,polyvinylpyrrolidone, cellulose, sterile water, syrup, and methylcellulose. The formulations can additionally include: lubricating agentssuch as talc, magnesium stearate, and mineral oil; wetting agents;emulsifying and suspending agents; preserving agents such as methyl- andpropylhydroxy-benzoates; sweetening agents; and flavoring agents. Thecompositions of the invention can be formulated so as to provide quick,sustained or delayed release of the active ingredient afteradministration to the patient by employing procedures known in the art.

The compositions are preferably formulated in a unit dosage form, eachdosage containing from about 1 to about 100 mg, more usually about 10 toabout 30 mg, of the active ingredient. The term “unit dosage forms”refers to physically discrete units suitable as unitary dosages forhuman subjects and other mammals, each unit containing a predeterminedquantity of active material calculated to produce the desiredtherapeutic effect, in association with a suitable pharmaceuticalexcipient. Preferably, the compound of formula I above is employed at nomore than about 20 weight percent of the pharmaceutical composition,more preferably no more than about 15 weight percent, with the balancebeing pharmaceutically inert carriers.

The active compound is effective over a wide dosage range and isgenerally administered in a pharmaceutically effective amount. It, willbe understood, however, that the amount of the compound actuallyadministered will be determined by a physician, in the light of therelevant circumstances, including the condition to be treated, thechosen route of administration, the actual compound administered, theage, weight, and response of the individual patient, the severity of thepatient's symptoms, and the like.

For preparing solid compositions such as tablets, the principal activeingredient is mixed with a pharmaceutical excipient to form a solidpreformulation composition containing a homogeneous mixture of acompound of the present invention. When referring to thesepreformulation compositions as homogeneous, it is meant that the activeingredient is dispersed evenly throughout the composition so that thecomposition may be readily subdivided into equally effective unit dosageforms such as tablets, pills and capsules. This solid preformulation isthen subdivided into unit dosage forms of the type described abovecontaining from, for example, 0.1 to about 500 mg of the activeingredient of the present invention.

The tablets or pills of the present invention may be coated or otherwisecompounded to provide a dosage form affording the advantage of prolongedaction. For example, the tablet or pill can comprise an inner dosage andan outer dosage component, the latter being in the form of an envelopeover the former. The two components can be separated by an enteric layerwhich serves to resist disintegration in the stomach and permit theinner component to pass intact into the duodenum or to be delayed inrelease. A variety of materials can be used for such enteric layers orcoatings, such materials including a number of polymeric acids andmixtures of polymeric acids with such materials as shellac, cetylalcohol, and cellulose acetate.

The liquid forms in which the novel compositions of the presentinvention may be incorporated for administration orally or by injectioninclude aqueous solutions, suitably flavored syrups, aqueous or oilsuspensions, and flavored emulsions with edible oils such as corn oil,cottonseed oil, sesame oil, coconut oil, or peanut oil, as well aselixirs and similar pharmaceutical vehicles.

Compositions for inhalation or insufflation include solutions andsuspensions in pharmaceutically acceptable, aqueous or organic solvents,or mixtures thereof, and powders. The liquid or solid compositions maycontain suitable pharmaceutically acceptable excipients as describedsupra. Preferably the compositions are administered by the oral or nasalrespiratory route for local or systemic effect. Compositions inpreferably pharmaceutically acceptable solvents may be nebulized by useof inert gases. Nebulized solutions may be inhaled directly from thenebulizing device or the nebulizing device may be attached to a facemask tent, or intermittent positive pressure breathing machine.Solution, suspension, or powder compositions may be administered,preferably orally or nasally, from devices which deliver the formulationin an appropriate manner.

The following formulation examples illustrate representativepharmaceutical compositions of the present invention.

Example 7

Hard gelatin capsules containing the following ingredients are prepared:

Quantity Ingredient (mg/capsule) Active Ingredient 30.0 Starch 305.0Magnesium stearate 5.0The above ingredients are mixed and filled into hard gelatin capsules in340 mg quantities.

Example 8

A tablet formula is prepared using the ingredients below:

Quantity Ingredient (mg/tablet) Active Ingredient 25.0 Cellulose,microcrystalline 200.0 Colloidal silicon dioxide 10.0 Stearic acid 5.0The components are blended and compressed to form tablets, each weighing240 mg.

Example 9

A dry powder inhaler formulation is prepared containing the followingcomponents:

Ingredient Weight % Active Ingredient 5 Lactose 95The active ingredient is mixed with the lactose and the mixture is addedto a dry powder inhaling appliance.

Example 10

Tablets, each containing 30 mg of active ingredient, are prepared asfollows:

Quantity Ingredient (mg/tablet) Active Ingredient 30.0 mg  Starch 45.0mg  Microcrystalline cellulose 35.0 mg  Polyvinylpyrrolidone 4.0 mg (as10% solution in sterile water) Sodium carboxymethyl starch 4.5 mgMagnesium stearate 0.5 mg Talc 1.0 mg Total  120 mg 

The active ingredient, starch and cellulose are passed through a No. 20mesh U.S. sieve and mixed thoroughly. The solution ofpolyvinylpyrrolidone is mixed with the resultant powders, which are thenpassed through a 16 mesh U.S. sieve. The granules so produced are driedat 50-60° C. and passed through a 16 mesh U.S. sieve. The sodiumcarboxymethyl starch, magnesium stearate, and talc, previously passedthrough a No. 30 mesh U.S. sieve, are then added to the granules which,after mixing, are compressed on a tablet machine to yield tablets eachweighing 120 mg.

Example 11

Capsules, each containing 40 mg of medicament are made as follows:

Quantity Ingredient (mg/capsule) Active Ingredient  40.0 mg Starch 109.0mg Magnesium stearate  1.0 mg Total 150.0 mg

The active ingredient, starch, and magnesium stearate are blended,passed through a No. 20 mesh U.S. sieve, and filled into hard gelatincapsules in 150 mg quantities.

Example 12

Suppositories, each containing 25 mg of active ingredient are made asfollows:

Ingredient Amount Active Ingredient 25 mg Saturated fatty acid glyceride2,000 mg  

The active ingredient is passed through a No. 60 mesh U.S. sieve andsuspended in the saturated fatty acid glycerides previously melted usingthe minimum heat necessary. The mixture is then poured into asuppository mold of nominal 2.0 g capacity and allowed to cool.

Example 13

Suspensions, each containing 50 mg of medicament per 5.0 mL dose aremade as follows:

Ingredient Amount Active Ingredient 50.0 mg Xanthan gum 4.0 mg Sodiumcarboxymethyl cellulose (11%) 50.0 mg Microcrystalline cellulose (89%)Sucrose 1.75 g Sodium benzoate 10.0 mg Flavor and Color q.v. Purifiedwater to 5.0 mL

The active ingredient, sucrose and xanthan gum are blended, passedthrough a No. 10 mesh U.S. sieve, and then mixed with a previously madesolution of the microcrystalline cellulose and sodium carboxymethylcellulose in water. The sodium benzoate, flavor, and color are dilutedwith some of the water and added with stirring. Sufficient water is thenadded to produce the required volume.

Example 14

Quantity Ingredient (mg/capsule) Active Ingredient  15.0 mg Starch 407.0mg Magnesium stearate  3.0 mg Total 425.0 mg

The active ingredient, starch, and magnesium stearate are blended,passed through a No. 20 mesh U.S. sieve, and filled into hard gelatincapsules in 425.0 mg quantities.

Example 15

A subcutaneous formulation may be prepared as follows:

Ingredient Quantity Active Ingredient 5.0 mg Corn Oil 1.0 mL

Example 16

A topical formulation may be prepared as follows:

Ingredient Quantity Active Ingredient 1-10 g Emulsifying Wax 30 g LiquidParaffin 20 g White Soft Paraffin to 100 g

The white soft paraffin is heated until molten. The liquid paraffin andemulsifying wax are incorporated and stirred until dissolved. The activeingredient is added and stirring is continued until dispersed. Themixture is then cooled until solid.

Another preferred formulation employed in the methods of the presentinvention employs transdermal delivery devices (“patches”). Suchtransdermal patches may be used to provide continuous or discontinuousinfusion of the compounds of the present invention in controlledamounts. The construction and use of transdermal patches for thedelivery of pharmaceutical agents is well known in the art. See. e.g.,U.S. Pat. No. 5,023,252, issued Jun. 11, 1991, herein incorporated byreference. Such patches may be constructed for continuous, pulsatile, oron demand delivery of pharmaceutical agents.

Frequently, it will be desirable or necessary to introduce thepharmaceutical composition to the brain, either directly or indirectly.Direct techniques usually involve placement of a drug delivery catheterinto the host's ventricular system to bypass the blood-brain barrier.One such implantable delivery system used for the transport ofbiological factors to specific anatomical regions of the body isdescribed in U.S. Pat. No. 5,011,472 which is herein incorporated byreference.

Indirect techniques, which are generally preferred, usually involveformulating the compositions to provide for drug latentiation by theconversion of hydrophilic drugs into lipid-soluble drugs. Latentiationis generally achieved through blocking of the hydroxy, carbonyl,sulfate, and primary amine groups present on the drug to render the drugmore lipid soluble and amenable to transportation across the blood-brainbarrier. Alternatively, the delivery of hydrophilic drugs may beenhanced by intra-arterial infusion of hypertonic solutions which cantransiently open the blood-brain barrier.

Other suitable formulations for use in the present invention can befound in Remington's Pharmaceutical Sciences, Mace Publishing Company,Philadelphia, Pa., 17th ed. (1985).

Utility

The present invention is directed to a method for inhibiting β-amyloidpeptide release and/or synthesis in a cell and a method for inhibitingγ-secretase activity. The invention is also directed to a method forpreventing or treating of neurological disorders associated withβ-amyloid peptide production. The method comprises the steps ofadministering to a host in need of such treatment a pharmaceuticalformulation comprising a therapeutically effective amount of a compoundof Formula I. The compounds of Formula I are useful in the prevention ofAD in patients susceptible to AD and/or in the treatment of patientswith AD.

Aβ production has been implicated in the pathology of Alzheimer'sDisease (AD). The compounds of the present invention have utility forthe prevention and treatment of AD by inhibiting Aβ production. Methodsof treatment target formation of Aβ production through the enzymesinvolved in the proteolytic processing of β-amyloid precursor protein.Compounds that inhibit γ secretase activity, either directly orindirectly, control the production of Aβ. Such inhibition of y secretasereduces production of Aβ, and is expected to reduce or prevent theneurological disorders associated with Aβ such as Alzheimer's Disease.

Compounds of Formula I are expected to possess γ-secretase inhibitoryactivity or inhibit Aβ production. Cellular screening methods forinhibitors of Aβ production, testing methods for the in vivo suppressionof Aβ production, and assays for the detection of secretase activity areknown in the art and have been disclosed in many publications, includingWO 98/22493 and WO 01/19797, EP 0652009, U.S. Pat. Nos. 5,703,1295,593,846; 6,211,235 and 6,207,710, all hereby incorporated byreference.

Compounds provided by this invention are useful as standards andreagents in determining the ability of a potential pharmaceutical toinhibit Aβ production. These can be provided in commercial kitscomprising a compound of this invention.

A compound is considered to be active if it has an IC₅₀ or K_(i) valueof less than about 100 μM for the inhibition of Aβ production.

Example 17 β-Amyloid Precursor Protein Accumulation Assay

An assay to evaluate the accumulation of Aβ is used to detect potentialinhibitors of secretase. The assay uses the N 9 cell line, characterizedfor expression of exogenous APP by immunoblotting andimmunoprecipitation.

The effect of test compounds on the accumulation of Aβ in theconditioned medium is tested by immunoprecipitation as described in WO01/19797. Briefly, N 9 cells are grown to confluency in the 6-wellplates. Test compounds dissolved in DMSO are added together with theaddition of radiolabel. The cells are incubated for 4 h at 37° C. in atissue culture incubator.

At the end of the incubation period, the conditioned medium is harvestedand pre-cleared by the addition of normal mouse serum and of protein ASepharose, mixed by end-over-end rotation for 30 minutes at 4° C.,followed by a brief centrifugation in a microfuge. The supernatant isthen harvested and transferred to fresh tubes containing of a monoclonalantibody directed against an internal peptide sequence in Aβ and proteinA Sepharose. After incubation overnight at 4° C., the samples arewashed. The pellet after the last wash is resuspended in SDS samplebuffer and boiled for 3 minutes. The supernatant is then fractionated onSDS gels. The gels are dried and exposed to X-ray film or analyzed byphosphorimaging. The resulting image is analyzed for the presence of Aβpolypeptides. The steady-state level of Aβ in the presence of a testcompound is compared to wells treated with DMSO (1%) alone. A typicaltest compound is considered active if it blocks Aβ accumulation in theconditioned medium, and has and IC₅₀ less than 100 μM.

Example 18 C-Terminus β-Amyloid Precursor Protein Accumulation Assay

The effect of test compounds on the accumulation of C-terminal fragmentsis determined by immunoprecipitation of APP and fragments thereof fromcell lysates as described in WO 01/19797. N 9 cells are metabolicallylabeled as above in the presence or absence of test compounds. At theend of the incubation period, the conditioned medium are harvested andcells lysed in buffer. Lysates are precleared with normal rabbit serumand protein A-Sepharose, followed by the addition of BC-1 antiserum andprotein A-Sepharose for 16 hours at 4° C. The immunoprecipitates arewashed bound proteins eluted by boiling in SDS sample buffer andfractionated by Tris/Tricine SDS-PAGE. After exposure to X-ray film orphosphorimager, the resulting images are analyzed for the presence ofC-terminal APP fragments. The steady-state level of C-terminal APPfragments is compared to wells treated with DMSO (1%) alone. A typicaltest compound is considered active if it stimulates C-terminal fragmentaccumulation in the cell lysates, and has an IC₅₀ less than 100 μM.

Example 19 Aβ Immunoprecipitation Assay

This immunoprecipitation assay as described in WO 01/19797 is specificfor γ secretase (i.e., proteolytic activity required to generate theC-terminal end of Aβ either by direct cleavage or generating aC-terminal extended species which subsequently further proteolyzed).Briefly, N 9 cells are pulse-labeled in the presence of a reported γsecretase inhibitor for 1 h, followed by washing to remove theradiolabel and the inhibitor. The media is replaced and test compoundsare added. Aβ is isolated from the conditioned medium and C-terminalfragments from cell lysates. The test compounds are characterized todetermine whether a stabilization of C-terminal fragments is observedand whether Aβ is generated from these accumulated precursor. A typicaltest compound is considered active if it prevents the generation of Aβout of accumulated C-terminal fragments and has an IC₅₀ less than 100μM.

Example 20 Cellular Screen for the Detection of Inhibitors of β-AmyloidProduction

Compounds of Formula I are assayed for their ability to inhibitβ-amyloid peptide production in a cell line possessing the Swedishmutation. This screening assay employed cells (K293=human kidney cellline) which were stably transfected with the gene for amyloid precursorprotein 751 (APP751) containing the double mutation Lys₆₅₁ Met₆₅₂ toAsn₆₅₁ Leu₆₅₂ (APP751 numbering) in the manner described in WO 94/10569and Citron et al (Nature, 360:672-674 (1992)). This mutation is commonlycalled the Swedish mutation. The cells, designated as “293 751 SWE”, areplated in Coming 96-well plates at 1.5-2.5×10⁴ cells per well inDulbecco's minimal essential media (Sigma, St. Louis, Mo.) plus 10%fetal bovine serum. Cell number is important in order to achieveβ-amyloid ELISA results within the linear range of the assay (about 0.2to 2.5 ng per mL).

Following overnight incubation at 37° C. in an incubator equilibratedwith 10% carbon dioxide, media were removed and replaced with 200 μL ofa compound of formula I (drug) containing media per well for a two hourpretreatment period and cells were incubated as above. Drug stocks wereprepared in 100% dimethyl sulfoxide such that at the final drugconcentration used in the treatment, the concentration of dimethylsulfoxide did not exceed 0.5% and, in fact, usually equaled 0.1%.

At the end of the pretreatment period, the media are again removed andreplaced with fresh drug containing media as above and cells areincubated for an additional two hours. After treatment, plates arecentrifuged in a Beckman GPR at 1200 rpm for five minutes at roomtemperature to pellet cellular debris from the conditioned media. Fromeach well, 100 μL of conditioned media or appropriate dilutions thereofare transferred into an ELISA plate precoated with antibody 266 (Nature,359:325-327 (1992)) against amino acids 13-28 of β-amyloid peptide asdescribed in WO 94/10569 and stored at 4° C. overnight. An ELISA assayemploying labelled antibody 6C6 (Nature, 359:325-327 (1992)) againstamino acids 1-16 of β-amyloid peptide is run the next day to measure theamount of β-amyloid peptide produced.

Cytotoxic effects of the compounds are measured by a modification of themethod of Hansen, et al. (J. Immun. Meth., 119:203-210 (1989)). To thecells remaining in the tissue culture plate is added 25 μL of a3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT)(Sigma, St. Louis, Mo.) stock solution (5 mg/mL) to a finalconcentration of 1 mg/mL. Cells are incubated at 37° C. for one hour,and cellular activity was stopped by the addition of an equal volume ofMTT lysis buffer (20% w/v sodium dodecylsulfate in 50%dimethylformamide, pH 4.7). Complete extraction is achieved by overnightshaking at room temperature. The difference in the OD₅₆₂ nm and theOD₆₅₀ mn is measured in a Molecular Device's UV_(max) microplate readeras an indicator of the cellular viability.

The results of the β-amyloid peptide ELISA are fit to a standard curveand expressed as ng/mL β-amyloid peptide. In order to normalize forcytotoxicity, these results are divided by the MTT results and expressedas a percentage of the results from a drug free control.

Example 21 In Vivo Suppression of β-Amyloid Release and/or Synthesis

This example illustrates how the compounds of this invention could betested for in vivo suppression of β-amyloid release and/or synthesis.For these experiments, 3 to 4 month old PDAPP mice are used (Games etal., Nature 373:523-52 (1995)). Depending upon which compound is beingtested, the compound is usually formulated at either 5 or 10 mg/ml.Because of the low solubility factors of the compounds, they may beformulated with various vehicles, such as corn oil (Safeway, South SanFrancisco, Calif.); 10% EtOH in corn oil (Safeway);2-hydroxypropyl-β-cyclodextrin (Research Biochemicals International,Natick Mass.); and carboxy-methyl-cellulose (Sigma Chemical Co., St.Louis, Mo.).

The mice are dosed subcutaneously with a 26 gauge needle and 3 hourslater the animals are euthanized via CO₂ narcosis and blood is taken bycardiac puncture using a 1 cc 25G ⅝″ tuberculin syringe/needle coatedwith solution of 0.5 M EDTA, pH 8.0. The blood is placed in aBecton-Dickinson vacutainer tube containing EDTA and spun down for 15minutes at 1500×g at 5° C. The brains of the mice are then removed andthe cortex and hippocampus are dissected out and placed on ice.

1. Brain Assay

To prepare hippocampal and cortical tissue for enzyme-linkedimmunosorbent assays (ELISAs) each brain region is homogenized in 10volumes of ice cold guanidine buffer (5.0 M guanidine-HCl, 50 mMTris-HCl, pH 8.0) using a Kontes motorized pestle (Fisher, PittsburghPa.). The homogenates are gently rocked on a rotating platform for threeto four hours at room temperature and stored at −20° C. prior toquantitation of β-amyloid.

The brain homogenates are diluted 1:10 with ice-cold casein buffer(0.25% casein, phosphate buffered saline (PBS), 0.05% sodium azide, 20μg/ml aprotinin, 5 mM EDTA, pH 8.0, 10 .mu.g/ml leupeptin), therebyreducing the final concentration of guanidine to 0.5 M, beforecentrifugation at 16,000×g for 20 minutes at 4° C. The β-amyloidstandards (1-40 or 1-42 amino acids) were prepared such that the finalcomposition equaled 0.5 M guanidine in the presence of 0. 1% bovineserum albumin (BSA).

The total β-amyloid sandwich ELISA, quantitating both β-amyloid (aa1-40) and β-amyloid (aa 1-42) consists of two monoclonal antibodies(mAb) to β-amyloid. The capture antibody, 266, is specific to aminoacids 13-28 of β-amyloid. The antibody 3D6, which is specific to aminoacids 1-5 of β-amyloid, is biotinylated and served as the reporterantibody in the assay. The 3D6 biotinylation procedure employs themanufacturer's (Pierce, Rockford Ill.) protocol for NHS-biotin labelingof immunoglobulins except that 100 mM sodium bicarbonate, pH 8.5 bufferis used. The 3D6 antibody does not recognize secreted amyloid precursorprotein (APP) or full-length APP but detects only β-amyloid species withan amino terminal aspartic acid. The assay has a lower limit ofsensitivity of about 50 pg/ml (11 pM) and shows no cross-reactivity tothe endogenous murine beta-amyloid peptide at concentrations up to 1ng/ml.

The configuration of the sandwich ELISA quantitating the level ofβ-amyloid (aa 1-42) employs the mAb 21F12 (which recognizes amino acids33-42 of β-amyloid) as the capture antibody. Biotinylated 3D6 is alsothe reporter antibody in this assay which has a lower limit ofsensitivity of about 125 pg/ml (28 pM).

The 266 and 21F12 capture mAbs are coated at 10 μg/ml into 96 wellimmunoassay plates (Costar, Cambridge Mass.) overnight at roomtemperature. The plates are then aspirated and blocked with 0.25% humanserum albumin in PBS buffer for at least 1 hour at room temperature,then stored desiccated at 4° C. until use. The plates are rehydratedwith wash buffer (Tris-buffered saline, 0.05% Tween 20) prior to use.The samples and standards are added to the plates and incubatedovernight at 4° C. The plates are washed three times with wash bufferbetween each step of the assay. The biotinylated 3D6, diluted to 0.5μg/ml in casein incubation buffer (0.25% casein, PBS, 0.05% Tween 20, pH7.4) is incubated in the well for 1 hour at room temperature. Avidin-HRP(Vector, Burlingame Calif.) diluted 1:4000 in casein incubation bufferis added to the wells for 1 hour at room temperature. The colorimetricsubstrate, Slow TMB-ELISA (Pierce, Cambridge, Mass.), is added andallowed to react for 15 minutes, after which the enzymatic reaction isstopped with addition of 2 N H₂SO₄. Reaction product is quantified usinga Molecular Devices Vmax (Molecular Devices, Santa Clara, Calif.)measuring the difference in absorbance at 450 nm and 650 nm.

2. Blood Assay

The EDTA plasma is diluted 1:1 in specimen diluent (0.2 gm/l sodiumphosphate.H₂O (monobasic), 2.16 gm/l sodium phosphate.7H₂O (dibasic),0.5 gm/l thimerosal, 8.5 gm/l sodium chloride, 0.5 ml Triton X-405, 6.0g/l globulin-free bovine serum albumin; and water). The samples andstandards in specimen diluent are assayed using the total β-amyloidassay (266 capture/3D6 reporter) described above for the brain assayexcept the specimen diluent is used instead of the casein diluentsdescribed.

Although the invention has been described with reference to thepresently preferred embodiments, it should be understood that variousmodifications can be made without departing from the spirit of theinvention.

1. A compound of Formula I:

or a pharmaceutically acceptable salt thereof, wherein X is selectedfrom the group consisting of:

in these structures, the bond marked with a wavy line denotes the pointof attachment of X to the rest of the molecule, wherein Q is —NR¹R²; R¹and R¹⁰, at each occurrence, is independently selected from the groupconsisting of: H, C₁-C₆ alkyl substituted with 0-3 R^(1a); C₂-C₆ alkenylsubstituted with 0-3 R^(1a), C₂-C₆ alkynyl substituted with 0-3 R^(1a),C₃-C₁₀ carbocycle substituted with 0-3 R^(1b); and C₆-C₁₀ arylsubstituted with 0-3 R^(1b); R^(1a) at each occurrence, is independentlyselected from the group consisting of H, C₁-C₆ alkyl, Cl, F, Br, I, ═O,CN, NO₂, NR¹⁷R¹⁸, CF₃; C₃-C₁₀ carbocycle substituted with 0-3 R^(1b);and C₆-C₁₀ aryl substituted with 0-3 R^(1b); R^(1b), at each occurrence,is independently selected from the group consisting of H, OH, Cl, F, Br,I, CN, NO₂, NR¹⁷R¹⁸, CF₃, C₁-C₆ alkyl, C₁-C₄ alkoxy, C₁-C₆ haloalkyl,C₁-C₄ haloalkoxy, and SO₂(C₁-C₄)alkyl; R² is independently selected fromthe group consisting of H, C₁-C₆ alkyl, C₃-C₁₀ carbocycle, C₆-C₁₀ aryl,R₃ is —(CR⁷R^(7a))_(n)—R⁴, —(CR⁷R^(7a))_(n)—S—(CR⁷R^(7a))_(m)—R⁴,—(CR⁷R^(7a))_(n)—O—(CR⁷R^(7a))_(m)—R⁴,—(CR⁷R^(7a))_(n)—N(R^(7b))—(CR⁷R^(7a))_(m)—R⁴,—(CR⁷R^(7a))_(n)—S(═O)—(CR⁷R^(7a))_(m)—R⁴,—(CR⁷R^(7a))_(n)—S(═O)₂—(CR⁷R^(7a))_(m)—R⁴,—(CR⁷R^(7a))_(n)—C(═O)—(CR⁷R^(7a))_(m)R⁴,—(CR⁷R^(7a))_(n)—N(R^(7b))C(═O)—(CR⁷R^(7a))_(m)—R⁴,—(CR⁷R^(7a))_(n)—C(═O)N(R^(7b))—(CR⁷R^(7a))_(m)—R⁴—(CR⁷R^(7a))_(n)—N(R^(7b))S(═O)₂—(CR⁷R^(7a))_(m)—R⁴, or—(CR⁷R^(7a))_(n)—S(═O)₂N(R^(7b))—(CR⁷R^(7a))_(m)—R⁴; n is 0, 1, 2, or 3;m is 0, 1, 2, or 3; R^(3a) is H, OH, C₁-C₄ alkyl, C₁-C₄ alkoxy, C₂ 14 C₄alkenyl or C2-C4 alkenyloxy; R⁴ is H, OH, OR^(16a), C₁-C₆ alkylsubstituted with 0-3 R^(4a), C₂-C₆ alkenyl substituted with 0-3 R^(4a),C₂-C₆ alkynyl substituted with 0-3 R^(4a), C₃-C₁₀ carbocycle substitutedwith 0-3 R^(4b), or C₆-C₁₀ aryl substituted with 0-3 R^(4b); R^(4a), ateach occurrence, is independently selected from the group consisting ofH, F, Cl, Br, I, CF₃, C₃-C₁₀ carbocycle substituted with 0-3 R^(4b), orC₆-C₁₀ aryl substituted with 0-3 R^(4b); R^(4b), at each occurrence, isindependently selected from the group consisting of H, OH, Cl, F, Br, I,CN, NO₂, NR¹⁷R¹⁸, CF₃, acetyl, SCH₃, S(═O)CH₃, C₁-C₆ alkyl, C₁-C₄alkoxy, C₁-C₆ haloalkyl, C₁-C₄ haloalkoxy, and C₁-C₄ halothioalkyl—S—;R⁵ is H, OR¹⁶, C₁-C₆ alkyl substituted with 0-3 R^(5b), C₁-C₆ alkoxysubstituted with 0-3 R^(5b), C₂-C₆ alkenyl substituted with 0-3 R^(5b),C₂-C₆ alkynyl substituted with 0-3 R^(5b), C₃-C₁₀ carbocycle substitutedwith 0-3 R^(5c), or C₆-C₁₀ aryl substituted with 0-3 R^(5c); R^(5a) isH, OH, C₁-C₄ alkyl, C₁-C₄ alkoxy, C₂-C₄ alkenyl, or C₂-C₄ alkenyloxy;R^(5b), at each occurrence, is independently selected from the groupconsisting of: H, C₁-C₆ alkyl, CF₃, OR¹⁶, Cl, F, Br, I, ═O, CN, NO₂,NR¹⁷R¹⁸; C₃-C₁₀ carbocycle substituted with 0-3 R^(5c), or C₆-C₁₀ arylsubstituted with 0-3 R^(5c); R^(5c), at each occurrence, isindependently selected from the group consisting of H, OH, Cl, F, Br, I,CN, NO₂, NR¹⁷R¹⁸, CF₃, acetyl, SCH₃, S(═O)CH₃, S(═O)₂CH₃, C₁-C₆ alkyl,C₁-C₄ alkoxy, C₁-C₄haloalkyl, C₁-C₄ haloalkoxy, and C₁-C₄halothioalkyl-S—; R⁷, at each occurrence, is independently selected fromthe group consisting of H, OH, Cl, F, Br, I, CN, NO₂, CF₃, phenyl andC₁-C₄ alkyl; R^(7a), at each occurrence, is independently selected fromthe group consisting of H, OH, Cl, F, Br, I, CN, NO₂, CF₃, and C₁-C₄alkyl; R^(7b) is H or C₁-C₄ alkyl; R¹⁴, at each occurrence, isindependently H, phenyl, benzyl, C₁-C₆ alkyl, or C₂-C₆ alkoxyalkyl; R¹⁵,at each occurrence, is independently H, C₁-C₆ alkyl, phenyl, benzyl,phenethyl, (C₁-C₆ alkyl)-C(═O)—, (C₁-C₆ alkyl)-O—C(═O)—, or (C₁-C₆alkyl) -S(═O)₂—; R¹⁶ is H, phenyl, benzyl, C₁-C₆ alkyl, C₂-C₆alkoxyalkyl, or C₃-C₆ cycloalkyl; R^(16a) is H, phenyl, benzyl, or C₁-C₄alkyl; R¹⁷, at each occurrence, is independently selected from the groupconsisting of H, C₁-C₆ alkyl, benzyl, phenethyl, (C₁-C₆ alkyl)-C(═O)—,and (C₁-C₆ alkyl)-S(═O)₂—; and R¹⁸, at each occurrence, is independentlyselected from the group consisting of H, OH, C₁-C₆ alkyl, benzyl,phenethyl, (C₁-C₆ alkyl)-C(═O)—, and (C₁-C₆ alkyl)-S(═O)₂—.
 2. Thecompound according to claim 1, wherein R¹═R²═H.
 3. The compoundaccording to claim 1 or 2, wherein R³ is —(CHR⁷)_(n)—R⁴; n is 0 or 1;R^(3a) is H, OH, methyl, ethyl, propyl, butyl, methoxy, ethoxy, propoxy,butoxy, allyl, or 3-buten-1-yl; R⁴ is H, OH, OR^(16a), C₁-C₄ alkylsubstituted with 0-2 R^(4a), C₂-C₄ alkenyl substituted with 0-2 R^(4a),C₂-C₄ alkynyl substituted with 0-1 R^(4a), C₃-C₆ carbocycle substitutedwith 0-3 R^(4b), or C₆-C₁₀ aryl substituted with 0-3 R^(4b); R^(4a), ateach occurrence, is independently selected from the group consisting ofH, F, Cl, Br, I, CF₃, C₃-C₆ carbocycle substituted with 0-3 R^(4b), orphenyl substituted with 0-3 R^(4b); R^(4b), at each occurrence, isindependently selected from the group consisting of H, OH, Cl, F, Br, I,CN, NO₂, NR¹⁷R¹⁸, CF₃, acetyl, SCH₃, S(═O)CH₃, C₁-C₄ alkyl, C₁-C₃alkoxy, C₁-C₂ haloalkyl, and C₁-C₂ haloalkoxy; R⁵ is H, OR¹⁶, C₁-C₄alkyl substituted with 0-3 R^(5b), C₂-C₄ alkenyl substituted with 0-3R^(5b), or C₂-C₄ alkynyl substituted with 0-3 R^(5b), R^(5a) is H,methyl, ethyl, propyl, or butyl; R^(5b), at each occurrence, isindependently selected from the group consisting of: H, methyl, ethyl,propyl, butyl, CF₃, OR¹⁶, Cl, F, Br, I, ═O; C₃-C₆ carbocycle substitutedwith 0-3 R^(5c), and phenyl substituted with 0-3 R^(5c); R^(5c), at eachoccurrence, is independently selected from the group consisting of H,OH, Cl, F, Br, I, CN, NO₂, NR¹⁷R¹⁸, CF₃, acetyl, SCH₃, S(═O)CH₃,S(═O)₂CH₃, C₁-C₄ alkyl, C₁-C₃ alkoxy, C₁-C₂ haloalkyl, and C₁-C₂haloalkoxy; R⁷, at each occurrence, is independently selected from thegroup consisting of H, F, CF₃, methyl, and ethyl; R¹⁶ is H, phenyl,benzyl, C₁-C₄ alkyl, or C₂-C₄ alkoxyalkyl; R¹⁷, at each occurrence, isindependently selected from the group consisting of H, C₁-C₄ alkyl,benzyl, phenethyl, (C₁-C₄ alkyl)-C(═O)—, and (C₁-C₄ alkyl)-S(═O)₂—; andR¹⁸, at each occurrence, is independently selected from the groupconsisting of H, OH, C₁-C₄ alkyl, benzyl, phenethyl, (C₁-C₄alkyl)-C(═O)—, and (C₁-C₄ alkyl)-S(═O)₂—.
 4. The compound according toclaim 1, wherein R³ is H, —CH₃, —CH₂CH₃, —CH₂CH₂CH₃, —CH₂CH₂CH₂CH₃,—CH₂(CH₃)₂, —CH(CH₃)CH₂CH₃, —CH₂CH(CH₃)₂, —CH₂C(CH₃)₃, —CF₃, —CH₂CF₃,—CH₂CH₂CF₃, —CH₂CH₂CH₂CF₃, —CH═CH₂, —CH₂CH═CH₂,—CH₂C(CH₃)═CH₂,—CH₂CH═C(CH₃)₂, CH₂CH₂CH═CH₂, —CH₂CH₂CH═CH₂,—CH₂CH₂C(CH₃)═CH₂, —CH₂CH₂CH═C(CH₃)₂, cis-CH₂CH═CH(CH₃),cis-CH₂CH₂CH═CH(CH₃), trans-CH₂CH═CH(CH₃), trans-CH₂CH₂CH═CH(CH₃);—C═CH, —CH₂C═C(CH₃), cyclopropyl-CH₂—, cyclobutyl-CH₂—,cyclopentyl-CH₂—, cyclohexyl-CH₂—, cycloproyl-CH₂CH₂—,cyclobutyl-CH₂CH₂—, cyclopentyl-CH₂CH₂—, cyclohexyl-CH₂CH₂—,phenyl-CH₂—, (2-F-phenyl)CH₂—, (3-F-phenyl) CH₂—, (4-F-phenyl) CH₂—,(2-Cl-phenyl)CH₂—, (3-Cl-phenyl)CH₂—, (4-Cl-phenyl) CH₂—,(2,3-diF-phenyl)CH₂—, (2,4-diF-phenyl)CH₂—, (2,5-diF-phenyl)CH₂—,(2,6-diF-phenyl)CH₂—, (3,4-diF-phenyl)CH₂—, (3,5-diF-phenyl) CH₂—,(2,3-diCl-phenyl)CH₂—, (2,4-diCl-phenyl)CH₂—, (2,5-diCl-phenyl)CH₂—,(2,6-diCl-phenyl)CH₂—, (3,4-diCl-phenyl)CH₂—, (3,5-diCl-phenyl)CH₂—,(3-F-4-Cl-phenyl)CH₂—, (3-F-5Cl-phenyl)CH₂—, (3Cl-4-F-phenyl)CH₂—,phenyl-CH₂CH₂, (2-F-phenyl)CH₂CH₂—, (3-F-phenyl)CH₂CH₂—,(4-F-phenyl)CH₂CH₂—, (2-Cl-phenyl)CH₂CH₂—, (3-Cl-phenyl)CH₂CH₂—,(4-Cl-phenyl)CH₂CH₂—, (2,3-diF-phenyl)CH₂CH₂—, (2,4-diF-phenyl)CH₂CH₂—,(2,5-diF-phenyl)CH₂CH₂—, (2,6-diF-phenyl)CH₂CH₂—,(3,4-diF-phenyl)CH₂CH₂—, (3,5-diF-phenyl)CH₂CH₂—,(2,3-diCl-phenyl)CH₂CH₂—, (2,4-diCl-phenyl)CH₂CH₂—,(2,5-diCl-phenyl)CH₂CH₂—, (2,6-diCl-phenyl)CH₂CH₂—,(3,4-diCl-phenyl)CH₂CH₂—, (3,5-diCl-phenyl)CH₂CH₂—,(3-F-4-Cl-phenyl)CH₂CH₂—, or (3-F-5-Cl-phenyl)CH₂CH₂—; and R⁵ is H,—CH₃, —CH₂CH₃, —CH₂CH₂CH₃, —CH(CH₃)₂, —CH₂CH₂CH₂CH₃, —CH(CH₃)CH₂CH₃,—CH₂CH(CH₃)₂, —CH₂C(CH₃)₃, —CH₂CH₂CH₂CH₂CH₃, —CH(CH₃)CH₂CH₂CH₃,—CH₂CH(CH₃)CH₂CH₃, —CH₂CH₂CH(CH₃)₂, —CH(—CH₂CH₃)₂, —CF₃, —CH₂CF₃,—CH₂CH₂CF₃, —CH₂CH₂CH₂CF₃, —CH₂CH₂CH₂CH₂CF₃, —CH═CH₂, —CH═CH₂,—CH₂CH═CH₂, —CH—CHCH₃, cis-CH₂CH═CH(CH₃), trans-CH₂CH═CH(CH₃),trans-CH₂CH═CH(C₆H₅), —CH₂CH═C(CH₃)₂, cis-CH₂CH═CHCH₂CH₃,trans-CH₂CH═CHCH₂CH₃, cis-CH₂CH₂CH═CH(CH₃), trans-CH₂CH₂CH═CH(CH₃),trans-CH₂CH═CHCH₂(C₆H₅), —C═CH, —CH₂C═CH, —CH₂C═C(C₆H₅), —CH₂CH₂C═CH,—CH₂CH₂C═C(CH₃), —CH₂CH₂C═C(C₆H₅), —CH₂CH₂CH₂C═CH, —CH₂CH₂CH₂C═C(CH₃),—CH₂CH₂CH₂C═C(C₆H₅), cyclopropyl-CH₂—, cyclobutyl-CH₂—,cyclopentyl-CH₂—, cyclohexyl-CH₂—, (1-CH₃-cyclopropyl)CH₂—,(-3-CH₃-cyclobutyl)CH₂—, cycloproyl-CH₂CH₂—, cyclobutyl-CH₂CH₂—,cyclopentyl-CH₂CH₂—, cyclohexyl-CH₂CH₂—, (2-CH₃-cyclopropyl)CH₂CH₂—,(3-CH₃-cyclobutyl)CH₂CH₂—, phenyl-CH₂—, (2-F-phenyl)CH₂—,(3-F-phenyl)CH₂—, (4-F-phenyl)CH₂—, phenyl-CH₂CH₂—, (2-F-phenyl)CH₂CH₂—,(3-F-phenyl)CH₂CH₂—, or (4-F-phenyl)CH₂CH₂—.
 5. A method for treatingAlzheimer's disease comprising administering to a host a pharmaceuticalformulation comprising a therapeutically effective amount of thecompound according to claim 1 or
 2. 6. The compound according to claim1, wherein X is


7. The compound according to claim 1, wherein R³, R^(3a), R⁵, and R^(5a)are hydrogen.
 8. The compound according to claim 6, wherein R³, R^(3a),R⁵, and R^(5a) are hydrogen; Q═NH₂; and R¹⁴, R¹⁵ are phenyl.